You only need a few bad actors to spoil it for the rest of us. 
(Disclaimer: This is all supposition. I have no inside knowledge beyond what I’ve read here like the rest of you.)
Often it’s the company (in this case, Sapien) that gets put on PayPal’s watch list, so Sapien switching to a different site won’t necessarily solve the problem. That would be like a physical shop getting on a watch list and then moving to another mall; that doesn’t work.
Some of Sapien’s other sites don’t have this problem because they were set up as different companies. Before you recommend that Sapien should list the fields you want on those other sites, that’d be like transplanting an infected organ into a patient who doesn’t have that infection. Maybe the patient will survive but maybe you can see how that might not be the wisest decision to make.