A Hindu friend has asked me why we offer animals which is a cruel thing that too in the name of God. I could not explain the issue to him. I told him that it is a sunnah of the Prophet Abraham (sws) but he said we could instead give away sweets etc and remember him.
A few points that might help:
1. It is not us (Muslims) who have decided to sacrifice an animal for God. It is God (according to us) who has ordered us to sacrifice an animal. So the question should not be "why you sacrifice" rather it should be "why your God orders sacrificing".
2. The core point of sarcificing is not to remember God. It is in fact a symbolic action (according to us Muslims instructed by God) to show that we are ready to sacrifice anything (including ourselves) for the sake of God.
3. The sacrificed animal is normally not wasted, it is consumed by people. It will not be consumed as an extra meal in addition to the amount that people usually eat during a day, it actually becomes part of the portion that a person normally eats in a day. The same animal would have been slaugtered to feed people any way. The only difference here is that it will be individuals (not meat wholesellers) who are buying the animal for slaughtering and they do this with the intention of sacrifice. This can only be considered as cruelty by vegeterians. We are not vegeterian.
4. Much of the meat of the sacrificed animal is given to the poor who are in need of meat (they are not vegeterian) and cannot afford it. In between giving sweats instead of meat to poor in order to save a goat, and slaughtering a goat in order to give proper food to a poor, I definitly go for the second one.