I met a lot of people that, even though they have strong reasons for being vegetarian/vegan, or even work saving/helping animals, etc. have failed to follow their principles and ended up including meat again.

Almost very vegetarian/vegan person I get to know has moved to vegetarianism for the same reasons I did (I'm moving in aswel):

 - Ethical reasons (i.e. not eating other animals)
 - Trying stop animal suffering (defending animals rights).

But, are there really good reasons other than this ones?

Am not saying they're not a great reasons, which I think they are, just trying to find out really good reasons.