[Excess reserve @ Fed](https://research.stlouisfed.org/fred2/series/EXCSRESNS)

In the past it was assumed that excess reserves should be kept around 0 and banks should be lending to each other as much as they are borrowing. The central banks would correct the negative or positive balance at the end of the day by lending or borrowing at premium rates, but that was only a short term solution.

Now we have 5 years of excess reserves at the Fed and a lot of articles about how banks don't care about cash deposits. 

Is this the failure of QE? The money being lent and given frivolously circles right back into the Fed in the form of excess reserve it seems.

Is this making it categorically impossible to raise real interest rates? Maybe interest rates could go up if a devaluation process was launched and inflation started climbing, but I'm more interested in understanding what makes the real interest rate move. 

Am I misunderstanding something or everything?