AMD's reputation for bad drivers was well earned
Not exactly correct. I mean, before AMD gets the consoles from SONY and MS, games where build on Intel+Nvidia hardware. So games where usually running better on that combination of hardware the day of their release. AMD needed some time to fix performance and bugs, but by the time they where coming out with a new driver for the new AAA title, all reviews and benchmarks from tech sites for that new AAA game where done. So, too little, too late, constantly.
For a short period around 2014 I think, AMD was enjoying a good period thanks to the fact that more games, because of the consoles, where build around their hardware. I think drivers back then where considered as good as Nvidia and we had some situations with problems with Nvidia drivers. But it was also a period where AMD was with half foot in the grave, selling Bulldozers and GCN refreshes. So, Nvidia had the money to secure much friendlier coverage from the tech press, with tech press finding in AMD the perfect chance to prove their independence from big companies. While the press would be accepting Nvidia's marketing and excuses to the letter, it would be attacking AMD at any chance given aggressively. Every multi page article attacking AMD, was passed to the readers as proof that that tech site publishing that article, was not fearing big corporations.
So, AMD's reputation was not something that it was totally their own fault. Tech coverage is extremely important in creating reputations and anyone living in a country where one political party is controlling the majority of press(probably every country in the world), can understand this. The fact that games where build in the part on Nvidia and Intel hardware was also important.
And then there are other reasons.
We have the close vs open ecosystem between these two companies. AMD's techs are open source, meaning Nvidia can optimize for them in a very short period of time. On the other hand, Nvidia's techs are close source, meaning AMD can't optimize as easily. That was giving one more advantage to Nvidia to look more capable than AMD.
And of course it's the difference in budget. AMD is fighting at the same time two bigger, wealthiest companies. It's not easy. If people don't want to understand that, maybe they will in case AMD does go bankrupt and we end up in a situation where we will have only one X86 CPU manufacturer and we will be hopping for someone else to take AMD's place and start producing competitive options fast, while in GPUs we will have an Nvidia monopoly and a miles behind Intel probably doing nothing really, considering that, in my opinion anyway, Intel is more interested in server GPUs than gaming GPUs.