Re: Windows 10 = Windows Vista
Make no mistake. Vista _was_ bloated, but it was the last of the major bloatware.
Up to that point MS was working on the basis that memory and cpu power would always increase so there was zero need to optimise anything. It was the rise of netbooks which torpedoed this strategy as Vista either wouldn't install on them or was so painfully slow noone would put up with it (2Gb was the practical minimum for XP once AV software is loaded and you want to run Office apps, 4Gb for Vista)
Win7 is primarily a result of putting Vista on a diet. It'll run in 2Gb (or less) like XP would and performed tolerably on netbooks (it even runs passably on a 768MB Tosh Satellite I keep around). At the same time MS took the paring knife to Office and its memory/cpu/gpu footprint was improved too.
As pointed out, i915 should never have been certified for Vista, but for that matter the i945 and the 3xx/4xx ranges were abysmal on it too thanks to their anaemic GPUs.
Win8 and 10 have pretty good memory/CPU footprints. That lesson has been learned. It helps that CPU core speeds haven't increased noticeably and nor have core counts on desktops, so MS can't use Moore's law as a software strategy anymore. The primary criticism is the awful tiles-based portable-use oriented desktop - which can be thrown out. They're also fairly reasonable on their GPU requirements, to the point that if you can run Win7 then Win10 is usually a better performer. That said: 3rd party software has continued to bloat.
It's almost as if MS has taken a leaf from IBM's playbook back in OS/2 days where they only let developers have the kinds of machines endusers would be using rather than the latest/greatest stuffed with infinite ram and top end CPUs. There's still a lot to criticise about Windows (and it's still slower than Linux on the same hardware) but the UI performance is fairly good.
The demise of Surface tablets and Windows phones may remove the handbrake from bloat though. Having to ensure stuff worked in those environments was beneficial for the rest of the software.