I agree with you completely!!
I have seen on many occasions crew taking everything from T Bags, bottles of water to bottles of Champagne, food, even toilet paper (true) and although I don't agree with it I would never say anything either, their day will come, and besides probably the worst reputation you can get for yourself is being known as a "dobber". Believe me, I've known a few and they are very unpopular. It can be a lonely working life.
What gets me though, still after all these years is why do crew do it. We get paid extremely well, have huge allowances yet people still choose to steal.
I have also been unfortunate to have known crew to steal from other crew bags. That really sucks, but in that case I would definately dob and wouldn't be ashamed of doing so.