As someone who's had a few stackexchange questions closed for various reasons, I think one solution (especially fitting for StackExchange) would be to mandate that a moderator who closes a question as inappropriate for the forum be required to supply an alternative forum (I did get suggestions when I asked on why my question was closed).

Ie, don't just delete/close my question - give me somewhere else I can ask it - or even migrate it - preferably to another stackexchange site. It's probably why stack sites like Programmers were created.

That would defray most of the downsides of "strict rules" based rejections.