Why are some people so negative?

I had posted on MSML about my doctor giving me the go-ahead to start taking this weight-loss product called Zylene 1.1 .
I have not only his full permission, but his full medical supervision as well.
Anyway, since I had seen Lacey shrinking away, I had been also discussing her weight loss and the product with a huge picture of the list of ingredients, in the girls private forum on the local Florida forums.
The thread is now almost 5 pages long, 20 posts per page, and one of the very first questions I asked was, 'is there anything in this list of ingredients that doesn't look safe?'
I asked that in my very first post as the thread starter, on page one.

I described Lacey's weight-loss success, and the cost of the pill, that no pill is the magic cure for fat etc, and a good discussion was going on, the girls were all excited, people started Googling it, and not a single person said a single negative thing until today.
This one girl who is much younger than I am, never married, no natural childbirths, lives an extremely healthy lifestyle of eating clean and working out all of the time.
She really does know her stuff when it comes to eating right and working out, she's great at it.
But she's also a bit of a pusher.

Let me explain.
You ever know someone who swears they smoked for like 20 years, quit cold turkey, and every single time they see you, whether or not you are smoking, if they know you smoke, they suddenly become the authoritative figure on how to quit smoking, how sick you are, how unhealthy you live your life.
Nag nag nag, pushing their oh so perfect healthy living on you when you didn't ask for their advice or opinion.

Before I left for my doc's today, this girl said there were a few ingredients that is in the Zylene that she would never put in her body.
I made the mistake of asking her what ingredient that was, and stressed that I had asked about the ingredient list in my very first post.
Big freaking mistake.
She then proceeded to talk about a single ingredient, chromium picolinate, which by the way, has been used in many different health supplements over the years, not just weight-loss drugs.
She explained how in test hamster cells, extremely large quantities of chromium caused oxidative stress and DNA damage, and the long-term effects of chromium has never been discovered or tested.
I thanked her for her answers as I always do, and had to leave for my appointment.

When I came back, posted to my blog, and then posted the news in that thread that my doc had given me the ok to go on the Zylene, and I did ask him about the chromium just so I could answer her question plus find out if it really is that dangerous.
He explained that in extremely high doses, it can be bad for some people.
I posted about him telling me to not take more than 3 per day, to start at one, move to 2 if I felt I needed it, and to never exceed the 3 per day limit.

Her next post to me was about using Fitday.com, and how it's helped her a lot, and then this question;
How is double or triple the amount of chromium you should be intaking not excessive?

I went back over my initial after doctor visit post, yup, I did explain about his orders to not take more than 3 per day, how I'd be under constant medical supervision, (I see him every 2 weeks. He will be doing weigh-ins, blood tests, blood pressure, check my diabetes etc) and how I had done my own research, asked him a ton of questions about this particular pill, got his ok, got tested by him, he will be supervising my weight loss, and she only saw the part about taking an excessive amount?!

I'll repeat what he said, "In extremely high doses, taking more than 3 per day in his opinion, can be bad for some people."
That doesn't say that 3 per day is the extremely high dose, and it's only for some people, not all, taking more than 3 per day could be bad for some people.

I'm going to be under constant medical supervision while I use this, I'll be seen every 2 weeks, be tested and monitored, I'm ok to go, I'm safe to go.
I'm not stupid about taking any weight-loss or other med for that matter.
I always look stuff up, I research even the medications that doctors have prescribed for me, I'm a well versed medical patient, who will be under medical supervision while doing this.

I really do appreciate how knowledgeable she is when it comes to healthy living and working out, she really does know her stuff, but again, I'm being treated by a doctor, under supervision, and I'm not an idiot.
I would never take anything that could potentially hurt me.
Chromium is actually ok for diabetics to take.

However, when chromium picolinate, which is the most bioavailable form, has been used, all of the studies have yielded positive results (in blood sugar, blood insulin and/or blood lipid [cholesterol and triglyceride] readings).

One of these studies, a 1997 study involving 180 type II diabetes patients in China, is a classic: it documented "spectacular" results in diabetes patients who took 500 mcg chromium picolinate twice daily. After four months, nearly all of the diabetes patients no longer had traditional signs of diabetes. Their blood sugar and insulin levels dropped to near normal--something that medications could not achieve.

In each 1 of these pills, there are 100mcgs of chromium picolinate, so 2 would 200mcgs.
A totally safe amount for diabetics which I am.
I am not an insulin taking diabetic, I have been controlling it through diet for quite a few years now, with the occasional screw up of course, but if chromium, even in an old study, has been shown to take away all of the traditional signs of diabetes by taking 500mcgs TWICE a day, then 200mcgs just once per day, is perfectly safe for me to take, and again, I'm under medical care.

I just don't understand these type of people who have to be so "perfect" about everything, think they know more than a doctor who knows this medication well, and is treating the patient.
It took all I had to not come back and say something snarky and mean, I often bite my tongue in the girls forum.
There's just something about putting a whole bunch of women together, even on line, that tends to bring out the kitty claws ya know?
And she just now responded to what I did write, which was just reiteration of all of the above information for the second time in that thread.
"You are definitely being smart about it. I hope it works for you. I know that if you were in perfect health you would be working out more intensely to get the results you want."

I just really want to know what part of I can no longer do traditional core workouts due to these titanium rods in my spine, was so hard to understand?
I can go for walks, I can use my elliptical, but sit ups? Crunches? Side bends?
Um, no.
Her reply is basically, that if I were in better health, which OMG, I'm so freaking sorry I'm not, that I would not be taking this pill, that the pill is cheating.
Maybe that's true, but she knows about my back surgery, it's been discussed multiple times, it was discussed again in that thread, so why the hell even say anything to me about being in perfect health?!?!

Why?!
Why.