Obviously, there is just one reason for GPU manufacturers to be bullish on crypto, and that's because of how they stimulate their sales significantly. If you look at how the prices of brand new GPU's have increased (almost doubled in some cases), and how the older (used) models are maintaining their value exceptionally well, it just shows that the crypto market isn't a joke anymore. As long as crypto keeps pushing forward, there is no doubt about this GPU hype to last for a longer while.
There are lots of problems with GPU mining for GPU manufacturers. The demand is very unpredictable, when altcoins rise, miners will buyout all GPU stocks and leave nothing left for gamers, when alts crash, mines will sell used GPU's or even RMA them, both resulting in losses for GPU manufacturers. This volatility of GPU market is causing some gamers to switch to consoles, and there's no simple way to fix it, because specialized GPU's for mining might be unattractive, since you can resell them to gamers. The best way for GPU manufacturers would be to start producing ASICs, but it's also a very risky investment, especially considering the uncertain and unpredictable legal status of cryptocurrencies.