Same for me. I think it is not wise to expect your users to be that fanatics, that they can't recommend any tool, without starting a flame war all the time. I mean there certainly are fanatics on the internet who fight with religious passion about the weirdest things, but I believe they are not the majority.
So just banning something that might cause trouble, but loosing all the benefits, I think was not a good decision.
But apart from that, I found lots of help on SO. But like others, not so much anymore, but mostly simply because I rarely need to look up things and the problems I do have are too obscure, for the main users, which are the target group, so I solve them by other means.
The utility became less and less over time. It can be done with a small enough and dedicated community behind it (the C++ book list), but without that amount of attention and dedication its not that good anymore.
There's also the number of questions. Stack Overflow back then got maybe a few hundred questions a day. You could glance over all of them in a tag in a page. Now it gets 8000 questions per day. Asking a recommendation question doesn't get your post there for a large community of experts. You're lucky if you've got a few minutes of visibility now.
Look back at one of those https://stackoverflow.com/q/22697 - "only" 14 answers to it... and look how many of them are saying the same thing. That's not useful. https://www.slant.co/topics/259/~best-mock-frameworks-for-ja...
Try https://www.slant.co for the recommendations - its designed for that.
The problem of "same answer repeated" becomes contrary to the "find the answer rather than scrolling through pages" when posts get sufficiently popular. Go through all the pages of https://stackoverflow.com/q/1711 and count how many times the mythical man month is mentioned. Unless you read through all 214 visible answers, do you know how much consensus exists from material on the last page?
They gave it a try - https://stackoverflow.blog/2010/12/17/introducing-programmer... and it veered off into unmanageable and at the end of the day, uninteresting https://stackoverflow.blog/2010/09/29/good-subjective-bad-su...
It had a really big initial peak, but people didn't stick around. https://meta.stackexchange.com/a/200144
There's a place for such questions, it just isn't Stack Overflow. It isn't the trash either... but its that the structure and the framework of Stack Overflow doesn't work for that sort of question.
The problem is that the endless debates tend to drive away the people who provide the answers. Look at the questions on https://ai.stackexchange.com and consider some of the older ones https://ai.stackexchange.com/questions?page=30&sort=newest to the newest https://ai.stackexchange.com/questions?page=1&sort=newest . They really had a problem with the... science fiction questions https://ai.meta.stackexchange.com/q/1283 and appear to have a done a strong change. Sure, those are interesting, but if one wants to ask questions of the experts, they need to ask questions the experts want to answer. There's a site that handles those questions better... https://worldbuilding.stackexchange.com/questions/tagged/art...
The main thing is that it takes some degree of moderation to keep the people who have the answers that people want. This means matching the site to the vision of the site that the people who have answers want to visit... and that's a lot of clauses. Without that moderation striving for what the site could be, you get https://answers.yahoo.com/dir/index?sid=396545663&link=list and there's a reason that experts tend not to go there and try to answer those questions.
As to the its a human issue, not a technical one - I'd suggest giving http://www.shirky.com/writings/group_enemy.html a read. The first of the three things to accept.
I've read Jeffs essay. I've used programmers.se and basically vowed never to go back after a few years because the moderation itself is piss poor (there one person gnat who's sole mission is to close every new question unless it's asked by one of their inner circle of buddies). It's really a joke. There's literally no reason for programmers to exist if not for expert opinioned discussions but they started cracking down on that and rendered the site useless. It's not just me either. Other good contributors have posted the same reasons for leaving in meta and in other forums.
I think you're conflating useful questions and good moderation with opinionated Q/A. I don't think anyone wants SE to be yahoo answers. But a question like what is the correct way to implement IO multiplexing is really useful. I think in SOs crusade to rid the site of opinion-based questions that are hard to handle, they threw the baby out with the bath water and got rid of some of the most useful discussions as a byproduct. Is SO dead? No. But I certainly get less utility out of it these days because I'm less willing to contribute when 90% of the time questions are met with instant downvotes and flags because someone didn't understand the finesse in a question and/or didn't assume positive intent so they could justify being pedantic assholes. I'm pedantic too. I draw the line at using it as a reason to be an asshole though.
I'm not saying SO didn't do its homework. But I am giving one data point that feels SO's usefulness has been marginalized because of the way the community has interpreted "no opinion based questions". I feel that zealotry has spilled out into the general air at stack overflow and it's no longer engaging or fun for many people to contribute these days. Take that for what it is, I guess.