I guess this is a business decision based on the fact that CAP generates a lot of new affiliate signups which supports a charge for being listed as affiliate program here.
If the affiliate signs up through a signature, this does not get tracked, and affiliate programs don’t see a value in being listed since no signups occur.
Looks to me like this is a tracking issue.
I have no knowledge of this, I am just saying what I think.
Seems like a “damned if you do, and damned if you don’t” type of thing.