Hmm, I think it's an excellent question.

For me, I don't think the people that do it are bad, just maybe troubled and in pain. I think, like any not particularly healthy habit, it can become a problem. Drinking alcohol in and of itself isn't bad, but when you can't stop or control it, you're in trouble.
When I do use si, it's cause something hurt too much and I couldn't find another way to deal. I don't feel particularly proud that I use it to deal, and I would be embarassed if others knew. With that in mind, I feel like I should learn better ways that I don't have to be ashamed of.
Guess it's up to each of us to decide for ourselves what works or doesn't. I wouldn't feel right telling someone they had to stop. Don't think it would work either.
Just my 2 cents, Quay