The standard position for graphics card has been horizontal, for many, many years. I don't think the standard position for a cigarrete lighter is upside down, to begin with.

Next, for your "solution" to work you need a special case that allows for the card to be installed vertically, which is not common.

It severely impacts performance. Also, once the junction reaches 110°, the fans also start spinning at max speed with no hope of actually cooling down the card enough. So yes, if you don't mind the noise from 100% fans always being on, your card being constantly unable to cool itself, and a 20-30% hit on performance on your 1200$ card... sure I guess?

>just get a 90 degree pcie adapter

And also buy a second PC case that actually has the slots for a 90 degree mount? Otherwise you'll need to take a hacksaw to the back of your computer.

> Just get a 90 degree pcie adapter

That's not trivial. How about I just buy a different card?