This has nothing to do with the developer or their game. I understand not wanting to use paypal, but take it up with Itch.io. it's a website problem, not the game's.
Honestly just surprised to see someone who doesn't have or use a PayPal in this day n age... it's become one of the easy use options for paying just about anything o.o
I have an account on paypal, but I don't like paypal as a company, so I don't keep any cards/bank accounts saved and I try to refrain from using them. I totally understand why someone would be upset that paypal is their only option to buy something.