Board Thread:Suggestions forum/@comment-172.3.45.153-20170117011347/@comment-26119768-20170117043124

I believe the reason this sort of thing has been turned down before is because mob AI with regards to doors is hardcoded into minecraft,  meaning that you can't modify it to recognize other blocks as doors. If these are implemented, then the player can use them, but npc's will see them as solid blocks, and won't be able to go through them.