Popper's criterion in a vacuum could seem to be exclusionary, but his philosophy of science involves his underrated idea of evolutionary epistemology. That all theories, seemingly pseudoscientific and the rest, compete to explain something, testable or not. Explanation is the most fundamental aspect, the rival statements compete to solve some problem in terms of how and why.

Read Popper's Ch. 1. Conjectural Knowledge: My Solution of the Problem of Induction https://roamresearch.com/#/app/infinitedays/page/tGbhrzsPK