Tsunami: Nobody "hates" fat people other than idiots.
But why the hypocrisy? Lets be honest here. Being overweight is very unhealthy. And ugly. Of course, guys can look good while overweight it if they're strong and well built, but not girls.
There's a huge difference between "putting on a few Christmas pounds" and being unhealthily overweight. These people were not banned from the site for being unhealthily fat, quite the opposite, they were banned for is not only quite healthy, but completely normal: gaining some winter weight.
I won't even dignify the sexist half of your statement with a response.
Tsunami: People who call you thin when you know you're overweight are not kind, but hypocrites. They don't care that you could improve your life expectancy or get a spouse, etc. They just want you to thank them while they laugh at you behind your back.
If someone were truly overweight or obese, no one would ever lie to their face and tell them they look thin. It is ridiculous to even address that kind of bald face lie as if it is somehow a rampant problem. However, there is absolutely nothing wrong with telling someone who has a healthy weight that they look good just the way they are. A "healthy weight" does not mean 0% body fat, six pack abs and a toned butt, a healthy weight just means that they weigh about the appropriate amount for their height and body type. They might have a little less muscle tone or a little more body fat than what is arbitrarily considered "perfect", but the fact is, our current standard of perfection for the human body is actually quite unhealthy and not what the human body is normally capable of. Our perception of what the body looks like, especially the female body, has become so warped over the years that we have completely forgotten what the human body is supposed to look like.
Here's a hint - nothing like this:
http://images.huffingtonpost.com/2009-10-15-350865366_7f308d82c91.jpg Its actually more like this:
http://www.gawker.com/assets/resources/2008/05/antmsize14.jpg