This is a fair point. But I think, and this is a large generalisation, that the answers to questions at an academic conference will be far more in-depth and int

This is a fair point. But I think, and this is a large generalisation, that the answers to questions at an academic conference will be far more in-depth and interesting than those at other confs. Not only that, but the calibre of questions asked is likely to be higher, resulting in better answers too. If the answer could be given as a comment reply on an equally banal blogpost level talk, then was the ticket price really worth the opportunity to ask the question face-to-face? I'd pay money to ask the leading expert at x university in machine learning a question. The leading "expert" in ClownJS? Not so much.