Many supermarkets have meat which is from animals which have been very cruelly treated and brutally slaughtered. This meat tends to be the cheaper meat and what choices have you got if all you can afford is the cheaper meat?
I have a fantastic butcher who actually is not that expensive and thinks he is a star because he was recently on BBC2 on a show comparing Sainsbury's with buying from local shops. Of course he was better! I know I might pay a little bit more but I know I can ask him where the meat comes from and he can tell me the history of it and how all he buys has been treated with some sort of respect before it is killed.
I am an ex vegetarian. I became a vegi when I was 14 and stopped when I was 23 and pregnant with my daughter. I was craving raost pork and nothing stopped the craving accept roast pork! The reason I became a vegi all those years ago was because of the unfair treatment of animals and that treatment is STILL happening yet we choose to put blinkers on.
I do not feel any guilt about eating meat anymore because my body obviously was in need of something which any that roast pork could provide? (I also craved tomatoes and oranges but not all together

)
I do think that something needs to be done about the way animals are treated but alas if cheap farming methods produce cheap meat and there will always be a need for that.