It really has become a norm and is very frustrating for customers, while there is simply a better way to do this - kill free plan for NEW customers, but grandfather existing customers. Or at least introduce some break-even (low profit margin) plan/tier to move existing customers to, no need to force them off the platform completely.

Yes, spammers are a big issue for all ESPs (my own biz in this space is no exception), but no need to throw the baby out with the bath water.