Earlier quoted context omitted.
I bet that most new users became new users to ask questions, including users that are not high rep veterans. I think that if you do what you propose, the site will just freeze in terms of user base.
Would it be reasonable to have an invitation from a person with x reputation bump someone up to the required rep to ask questions? One could spend time in meta, and the chat room where people could get to know them. For the well-intended but naive, this would encourage getting to know the site and expectations of the culture. For the people who are just a bad fit, they could be filtered with minimal effort. Would the…
One can easily overcome that with ten skillful edits, 2 upvotes (or 1 upvote and an accept) on an answer, or 4 upvotes on a question (20 rep is required for chat).
It's fairly easy for an individual to get into the chat, if they want.
That barrier does keep spammers from flooding the chat, though. And if you consider it an interview process, that's what the earning of reputation points accomplishes, and I'd argue it does so rather elegantly.