I don't agree with using CP. Matt said it's not a good metric and it's going to be removed

It will probably hurt card rentals because it excludes rentals from the CP requirement. I think the rental systems in SPL is one of it's strengths and we shouldn't take steps to make it less effective

It's a band-aid solution that doesn't solve the underlying issue. Fundamentally the problem is that large numbers of low-value accounts out-earn fewer, high-value accounts. In other words, horizontal expansion (number of accounts) is better than vertical expansion (upgrading collection).
There's solutions to this that don't add arbitrary rules or hurt the rental market.