So that when I'm in a cave and need a door but don't have wood I can make these doors.
Maybe they could do something special like being openable by undead skeletons or zombies if they bang on them long enough. which could be cool for horror maps

See CONTRIBUTING.md, which you should've read before creating an issue:

Unless requested by a team member ahead of time, suggestions are not accepted here. Please check out the Quark subreddit and post them there instead.