I should have known something was up when Stripe sent out the email survey two days ago about subscription pricing. Very strange that you only sat on those results for a day before pulling the trigger on this. Interestingly, some of the survey answers included concepts of a free tier.
To me, the percentage makes little sense. You could be running 1,000,000 $10/mo subs, or 1,000 $1,000/mo subs and the cost is the same. This pricing model hits high value subscription companies significantly harder, even though Stripe's costs are lower.