I think the trap here, a function of scaling any business, is that what's best for most of your customers isn't necessarily best for all of your customers. Another perspective is that what's right for your 2013 customers isn't necessarily the right thing for your prospective 2014 customers.

One possible outcome of your decision is that you're optimizing for customers who have repeat business and against customers with one-off business. That may well be right thing for Stripe.

I am a strong supporter of opinionated software but I think that view has to be colored with "this solution will be wrong for some customers" and "we are not building a solution for every customer". I imagine these assumptions are implied in your explanation above.