As amusing as it is to see Elon fail, letters like “X” shoud not be trademarkable. Just one indicator that we’re truly reaching capitalist extremism levels of insanity.
Also, how the hell could Microsoft get a patent for X in 2003 when X has been around since 1984, and is pretty much a direct competitor? This makes no sense at all.
The law is a weapon of the rich. You don't have to be right, you just have to be able to afford out-lawyering your competition. Patents are especially revolting.