Well, maybe they bring some kind of competition in the world of merchant acquirers, but they are raising interchange prices, not lowering them. True competition lowers prices.
Have you looked at the mess that is FirstData> ISO> ISO> ISO?
Sales has been difficult to scale in this market for so long, it has relied on lots of layers of independent sales people. I would argue Square will bring some efficiency to this market.
I'm not sure you took my point. FirstData is the largest merchant acquirer in the country; it's now privately owned, bought for $30B. It used to be part of American Express, as an interesting sidenote. These are entrenched industries, and you can't simply change them over night.
Out of curiosity, have you worked for a +$10B business?
Also, no, I haven't worked as an employee for a $10 billion company, nor do I have any desire to.
And yes, you can change entrenched industries overnight; that's the point of technology entrepreneurship, and it's why many of the people who frequent Hacker News bother coming at all.
Lastly, I've noted that in other parts of this conversation you claim to be an expert on payments--so who are you, again?