Especially since any focused site that came up to do this would almost certainly put way more barriers to entry into the community than reddit (which still allows you to create a new account virtually instantly, with no email verification) has.
I think there just aren't enough interesting people doing Q&As for a business model based on this to make much sense.
Reddit's AMA format is pretty bad, especially if it's a woman/girl answering questions, though.
voomly.com
Fred Wilson wrote about them here: http://www.avc.com/a_vc/2013/01/voomly.html
(The "Woody Harrelson"/Rampart AMAs would be the norm if not for the chaotic nature of reddit).
I would like to marry you... or just buy a pair of your
used undies. It's funny that people actually do that.
http://www.reddit.com/r/IAmA/comments/17yd4k/iam_emmy_rossum...Just hi-larious.
And if it's a trade-off where more "impulsive" comments are deleted, then I prefer that to subjecting female respondents to constant come-ons from pubescent, sad human beings.
I think it's clear what Emmy Rossum prefers.
Emmy Rossum went to reddit for an AMA, and used the site's commenting functionality to ask people not to be rude. She did not cancel her AMA, ask to have the rude comments deleted, etc.
Not the best interface, but it is what you asked for...
The context link will show the comment he is replying to.
Why hasn't reddit's AMA been surpassed by a dedicated AMA site with a user interface designed for AMA?