This statement fully captures the stark difference between Stripe and Balanced. Stripe is led by engineers who want to improve the payments infrastructure. Balanced is led by businesspeople who want to hit it big. Stripe just so happens to be a business as well. Nothing wrong with either, but that should point you toward which company has the developer's true interests at heart :)
Bias alert: I have a Stripe account, but not a Balanced account.
I think it's disingenuous to not suggest that Balanced doesn't 'have the developer's true interests at heart.' They've been really pushing the hypermedia API stuff, which is technologically exciting, as well as doing the whole 'open company' thing, which is taking the concept open source to interesting places.
I don't know anyone who works at either company so maybe one of them is full of nasty people who hate their customers and one is full of lovely people who don't care about making profit - but that's very unlikely. Much more likely is that they both want to maximise their profits, they both understand that offering a good service to their customers is the way to do this, and both approach this in different ways. And frankly the fact that a Stripe employee said a nice thing about them as opposed to "fuck them use Stripe" doesn't give any clue on the subject, it just says this person is a.) polite and b.) not an idiot.
Hint: It's Stripe.