With companies like Spreedly to provide almost-Stripe-quality APIs and PCI-compliant card vaulting at only a flat cost, and a massive amount of "merchant account providers" a quick Google away that can hook into Authorize.net and then into Spreedly, you can end up at 1.75% or less depending on your industry, and the flexibility to dynamically route transactions to merchant accounts (including Stripe itself) based on anything from geography to your own notion of fraud/return risk.
Stripe has far and away the best developer and administrator experience in the industry - it surprises and delights. But this doesn't make it the right solution for all businesses. Its genius was that it entered the zeitgeist as such.