People can get made at me if they want to, but I'm not going to share answers to homework
It's probably up to you about sharing your own answers, but why don't you want to share the answers to the homework?
There is a part of me which is cautious of rules and regulations.
It is okay to be concerned about sharing homework answers. Some teachers will really care and will consider it cheating and it could get you in serious trouble.
How come they never allow us to just share freely?
Homework is intended to be a lesson, and if you just copy someone else's answers you don't learn as much. That's why sharing the answers can be considered cheating, and why you can't just share the answers with each other.