Gil sinks don't need to make sense to you, they need to make sense to the economists hired by SE.

300k is nothing, you can make 300k very easily without ever touching crafting or gathering, if you're getting kicked from free companies that often there are other things you probably should be worrying about.

And for the OP, they gave a lore reason just so it makes sense for roleplayers, but that's not the real reason, someone in the first page already stated what's the real reason, inn rooms are meant to be low resource instances, there's absolutely no need to take server resources from the rest of the game just so you don't have to click two buttons and leave the inn room to craft something.