And even then, people were never against most of it. Scrollbar thumbs with grip stipple? Checkboxes that fill in with a roundrect rather than a checkmark? Buttons and tabs that have an inline ring-highlight "intent" color to them, akin to the fill color on modern Bootstrap theme buttons? These were all parts of the Luna theme as well — and people liked them. (And, IIRC, they were often sad that these parts got deactivated when reverting to the Windows Classic theme, and often asked if there was some hybrid theme that kept these.)

With Luna, I think people were mainly just reacting negatively to two things:

1. the start button being big and green and a weird blob shape; the start menu it opens having a huge, very rounded forehead and chin — and both of these having a certain "pre-baked custom PNG image 8-way sliced in Photoshop and drawn by parts" look that you'd see used on web pages in this era. This made the whole UI feel very "non-brutalist" — form not following function, the way it did in Windows Classic (where the theme was in part designed to optimize for as few line-draw GDI calls as possible.)

2. both the taskbar and window title bars being vertically thicker, and having a vaguely-plastic-looking sheen to them to "add dimensionality."

And my hypothesis is that, of these, it was mainly the "vertically thicker" taskbar+window decorations that upset so many people.

This was an era where many screens were still largely 1024x768, even as monitor sizes were growing; so "small was cool" [and legible!] Websites baked their text into images using 8x5 pixel fonts; Linux users used tiny fonts and narrow themes in fvwm/blackbox/fluxbox, etc. In that era, a title bar stealing thirty whole pixels was almost blasphemy. (Same problem with the Office XP ribbon. Microsoft's visual designers must have been too far ahead-of-the-curve in what kind of resolutions their graphics cards supported, I think.)

I think, if there was an alternate version of Luna that also shipped with XP, that just narrowed the taskbar and window caption bar to the Windows Classic dimensions... then Luna would have been universally acclaimed.

> The "Fisher-Price" design language was unpopular, but ISTR you could turn off most of the eye candy and get a the Windows 2000 design language. Pretty sure that was like the first or second thing I did with both XP and Vista.

Ah, it is very likely that that's what I did, and so why I don't remember anything notable about it.

Yes, it was obvious that the Windows 8 focus on tablets (and Windows phone) would not work well with Aero, since their GPUs were lacking.