That is what disruptive innovation looks like. "Oh look, a multi-billion dollar problem people were trying to solve by getting two sides of the market to simultaneously ubiquitously install new hardware. How about we solve it with stuff they already own plus new software instead?"
As long as Square uses cards for funding, it will be robbing the poor to pay the rich just like every other card company. To me, "disruptive" in the payments world means no cards, period.