As someone who remembers the early days of D&D, and who gamed through the transition from story-based character-concept communication to mechanics-based, through the time of umpteen gajillion kits and classes and feats to the "book bloat" of 4e, it feels to me like the designers of 5e deliberately made 5e a mechanically simpler, class-based system which has infinitely more in common with OD&D and AD&D than any other version
Though I have nearly the same breadth of experience (starting in '80 with Basic & 1e AD&D), I have a different feel for complexity with respect of AD&D and 5e. Maybe because I branched out into a lot of other game there in the 90s & late 80s? Maybe due to disease or mental defect on my part. IDK.
That is, in absolute terms, AD&D was insanely complex, and not just complex, but needlessly complicated. (Don't get me wrong, 1e AD&D was my first love of RPGs, and still favorite edition, if I must pick a favorite for that reason, but I will hold that at arms length and look at it analytically, and when I do, I have to acknowledge that it's insane.) For one thing, it was the first RPGs, and RPGs are necessarily more complex than traditional board games like Monopoly or whatever, just enormously moreso. For another, D&D was essentially 'experimental' until 2e, at least.
And, of course, in reaching for the 'feel' of classic editions, 5e has embraced some of their complexity, even including some (thankfully eschewing a lot, like attack matrixes, percentile checks, armor vs weapon adjustments, random psionics, etc, etc, etc) of the /needless/ complexity that complicated it.
The result, though, feels like the classic game, so if you played the classic game, it feels familiar. And the ease of slipping into something familiar is very like that of picking up something simple.
And it's not like that's even a good strategy 'only' for the long-time and returning player. The best way to learn D&D is to play with an experienced DM. By attracting and meeting the expectations of a lot of experienced players & DMs, 5e provides new players with a better chance at having a good first experience at the table of one of those experienced DMs.
and that the optional multi-classing and feats rules were tacked on to specifically appeal to those whose enjoyment of the game is predicated on optimization.
I think it was more specifically to appeal to fans of 3.x, and it's telling that those two components stand out as explicitly optional, while bits and pieces of 4e that could have been made optional like Healing Surges (in the bowdlerized form of HD) became core.
I think 5e, to a small extent, wrote off the most ardent fans of 3.5/PF (or perhaps the most-resentful-of-WotC fringe of those fans, to put it another way).
... 5e is bad at being Pathfinder!
Well said. Ironically, though, both 5e & PF are quite good at being D&D, IMHO.
I rather agree. I don't think it'll unbalance the game, per se.
It'd have to balance it in the first place, then unbalance it. ;P
I think it's an attempt to turn one game into another, and I think that's a terrible thing to do when all you have to do to be happy is play the game you like.
But it's a necessary thing for 5e to present tools to do, because it's not exclusively for fans of the classic game, but also those fans of the modern game who aren't so bitter that they refuse to give WotC a 2nd (5th? 13th?) chance.
Thus the tentative 'modular' design, with things like Feats and MCing presented, but explicitly 'optional' and any subsequent supplements very optional, indeed.
We have the stripped-down, basic version of the game in a pdf.
We have the rich, 'classic' (A)D&D version of the game in the non-optional PH rules.
We have a taste of the more option-rich, system-mastery-rewarding version of the game in the optional PH & DMG rules.
But, there's plenty more that could be released, and hopefully will be, without having to have the least impact on the basic-pdf or the PH-only campaigns out there.