Understandable, but as I said, how do you insure top-grade talent? How do you find people who are worthy of the title and can be trusted not to abuse it? I mean, there have been a couple of prior cases where "stand-in" Batmen such as Jean-Paul Valley didn't work out too well.
And then you have the chance of another Jason Todd mental stability issue.
I'm sure Dick's Batman would make a one liner like
"As if we didn't have enough psycho's wearing bat masks..."
One Batman goes rouge and decides to whip out all the others.