You call it nostalgia, I call it different taste. I'm not a power gamer, and I get most of my at-table satisfaction from strategic play and role-playing rather than maximized PCs. I've always had a ton of fun and managed to be very effective playing exactly the PC classes that people tend to condemn on the message boards.
What's more, as a DM, I never, ever have problems with fighters or rogues or monks finding ways to contribute meaningfully to the story, the adventure or to the combats. It has literally never happened in one of my games that the casters took over the story and eclipsed everybody else.
What HAS happened at my table is that OP'd builds have messed up party balance dramatically...and bizarro options that I hadn't anticipated have messed up the flavor of the adventures.
That's fixable - it's not the end of the world.
But I'm not exaggerating or fudging when I say that the abstract, numeric DPR-type powergaming analysis of PC builds that you describe has never been an issue at my table, while the brokenness issue of complex power builds has been repeatedly.