They are saying, "______ (blank) is a bank", not X, formerly Twitter.
Again, X is the dumbest possible name for aything, I will never user it, just call it Twitter if you have to.
No one is saying X, the platform formerly know as Twitter, is a bank.
Honestly how is it even possible to name a company or a product after a single letter? That shouldn't even be trademarkable.
It's marketing. The dumber and more obnoxious something is, the better it is, because people talk about it. Just look at your own comment - as much as you dislike the name, it's you who brought up X/Twitter into the conversation, reminding us about the brand at this time and place. The name is working as intended.