Because the problem was never that the P.SE community was unhappy with P.SE. That would have given rise to discussion here, and a whole lot more participation in the various "What's on-topic?" threads. But by and large, P.SE users wanted the sort of content that was showing up on the site, and with a handful of exceptions were content to just participate on the site itself.
No, the problem was that P.SE - the content, the users, the very idea behind its inception were seen as distasteful and embarrassing by The Stack Exchange. The perception of the StackExchange brand has become a concern for them, and a site seen as frivolous didn't fit with the image they hoped to project. It's anyone's guess why they let the Area51 proposal make it all the way through commitment; perhaps they thought it would fizzle in private beta and could then be swept under the rug? But once the site went live and immediately garnered popular support it became hard for them to ignore it - and so they had a problem.
Hence the discussion on Meta. Asking P.SE users to solve their own problems wouldn't have been a useful thing to do, as the problems were not those of the P.SE users.