Because they took the Kemetic belief system and didn't have one ounce of respect for it as it was, instead they tried to use it to justify their own belief system, instead of just letting their beliefs be their beliefs, and leaving Kemet alone. They used our gods to validate theirs, and I see that as awful, not admirable. I do not believe Djehuty is Hermes, nor do I believe Aset is Diana. That is a disservice not only to the Egyptian gods, but the Greek ones as well. The Greek gods are their own unique personages, and it's a disservice to them to act as though associating them with other deities validates their worth.
A) I thought KOs were allowed to have a variety of beliefs. Alexandria was the learning center of the world at its heyday. I don't see how you could be offended by the swapping of culture.
B) What about other cultures? I've heard of Set being compared to Ba'al and Yhvh, for example.