They do, presumably because the kernel is so much better and more modern. And I guess because of DX. Then again the May 2016 update for Win7 installs the newest version of the kernel, so...Do ppl willfully switch from win 7 to 10? My experiences with win 10 is that its like a windows 7 where they removed your power to choose and make stuff hard to access (probably with the mentality "lets not scare dumb users")
I think the description that you give is rather accurate. It's like fixing the things that they broke with Windows 8, but mixing a tiny amount of them in, so it still looks like Windows 7 again... almost, but not exactly. Without Aero effects, but you still pay the cost for a compositing window manager (why... I cannot tell you).
Plus some extra stuff that is admittedly very nice and which I'd like to have too (including the whole VM stuff, run-off-USB, Unix compat layer including NFS support which allegedly existed since pretty much forever (at least since Win7, but I never managed to find it!) and newest DX and a new, presumably better, Internet Exploder).
Plus... an awful lot of stuff that you probably don't want but for which you have no option of not having, and entirely inacceptable license terms which basically say Microsoft own all yer stuffs.