Faster Payments: Is There a Business Case?

The Federal Reserve System has embarked on a project of exploring the possibility of faster retail payments in the United States.  A similar move has occurred with the UK Payments Council.  At the same time, the Electronic Payments Network is rolling out a faster version of ACH.

Here's what puzzles me:  what on earth is the business case for faster retail payments in the United States?  The U.S. payment system works incredibly well. Yes, it has flaws: the interchange system is unfair and security is atrocious. But those aren't really speed issues.  Real-time authentication is a security issue, but that's separate from speed of payment clearance and settlement.  

Now, it's true that the US lags behind other countries in terms of mobile payment technology.  We don't have anything like Kenya's m-Pesa mobile payment system. But there's a reason for that:  we don't need m-Pesa in the US because we already have a functioning retail banking system, and our banks are better safety-and-soundness risks than our telecom operators.  (Kenya's government owns a large share of m-Pesa, making it quasi-guarantied, I guess.)  

So readers, tell me, what am I missing?  Is there a business case, or is this just about chasing shiny bells and whistles and wanting to have the latest technology just because?  My sense is that we're seeing an "iPhone effect" of wanting the best and newest, even though the current system is just fine.