Windows XP
When Windows XP first released, people criticized it for having a theme that they hadn’t seen before in Windows. People thought it was very kiddish and appealing to children, not being taken as seriously for the large userbase of the time. There were also criticisms about how fragile Internet Explorer was (I’m not kidding, I was there and Internet Explorer back then was at its most insufferable.).
But these days, just because of how bad Windows 8, 8.1, 10 and now 11 have been, people have praised Windows XP so much.


The Star Wars prequel trilogy.
There was a looooot of vitriol, especially for Ep. I. And with each release it always seem to get louder, and frankly a lot of it was toxic and inexcusable.
Nowadays I see a lot of nostalgia around them, especially from Millennials who grew up on these three films, much like the GenX kids grew up on IV, V and VI. And a lot more kindness towards the actors too, especially Hayden.