Which is more a demonstration of the echo-chamber of these forums and the tiny subset of players on them, than the actual quality of those features. It's also a demonstration of "people don't comment much on things which they like but which aren't apparently in danger of being removed or changed" - I agree with you on healing beams being terrible, but I'm also certain that if Frontier said "we've listened to 'the players' and are removing them" there would be an instant and massive backlash from the players who had really liked them but felt no particular need to start a public healing beams fan-club on the forums without that announcement.
Powerplay, sure, it's got some major well-known design flaws [1], virtually no maintenance for years, and no real roadmap for addressing those issues. I never personally got into it either - though I might have, if it hadn't come out while I was taking a break from the game. But it still has considerably more players taking part in it and using it than it has players coming on to the forums to say how bad it is. (There is overlap between those groups, of course - a lot of complaints about Powerplay are coming from people who like the concept but are frustrated by aspects of the implementation)
The ADS change was controversial, not universally unpopular. Any major change to an existing mechanic would do that. The changes to engineering in 3.0 were heavily criticised in certain areas before release from several angles ... now that they've had time to settle in, there doesn't seem much call to go back to how it was in 2.4. And it's also worth remembering just how much the pre-3.3 exploration mechanics were criticised as boring "honk and point" before Frontier showed an alternative to that. (Another example of "people don't comment much on things which they like but which aren't apparently in danger of being removed or changed")
Look at it a different way: pretty much every major feature - Powerplay, CQC, Engineers, Multicrew, Thargoids, C&P, new Exploration - has been criticised heavily on release and often a long time afterwards on these forums. (I have quite a bit of criticism of many of those features out there myself). But there's no demand to roll back to 1.2 before those features were introduced. And the game sales in terms of base-game accounts sold per year have been basically constant at ~750,000/year for the last four calendar years, with 2018 being slightly stronger than average. There's a lot in Elite Dangerous I wouldn't have done that way - and I mean a lot - but Frontier are the ones with the strongly selling game in a niche market, not me, so over the years I've come to admit that they may have a point.
[1] Though much less player consensus, even among "Powerplay experts" as to what a fixed version would look like.
