Microsoft being a true monopoly might have struck fear in the timid souls of Intel executives that they would go headlong for AMD.
Or Google had this opportunity for years, and half-assed ChromeOS. Or AMD. Or Dell/HP/IBM who sold enough x86 to have money on the side.
I don't buy that it would have been hard. Look at what Apple did with OSX with such a paltry market share and way before the iPhone money train came. First consumer OSX release was 2001.
Sure, Apple had a massive advantage by buying NeXT's remnants and Jobs's familiarity with it and the people behind it, but remember that Apple's first choice was BeOS.
So anyone looking to push things could have got BeOS, or an army of Sun people as Sun killed off Solaris. The talent was out there.
Instead here we sit with Windows in a perpetual state of the two-desktop tiled/old frankenstein, Linux DE balkanization and perpetual reinvention/rewrite from scratch, and OSX locked on Apple.
Yeah of course it was possible for Intel to do more, but they're clearly largest contributor to Linux graphics stack anyway.