I see a lot of people trying to coerce others into being "happy" all the time, as if people can just choose what to feel and when.
To use an extreme example to make my point, if I treated somebody like shit for years, it'd be normal if they became bitter or depressed or angry over time. Go ahead and talk about how nobody wants to hang out with "negative" people like this, or how "it only hurts themselves to feel this way," whatever other hippie rhetoric.
Still, the least people can do is empathize with why somebody may be feeling this way. Action-reaction. Most of all, if it were as easy as flipping a switch, everyone would choose to feel great about everything all the time. Then again, I guess that's one of the main reasons people use drugs.
Note that I'm not against self-improvement, it's just that some things can't be as easily helped. If someone is feeling bad about their physique, that can be molded somewhat. Other things, not so much.