I think alot of people are heavily loving batman tas and dcau for reasons beyond me.
The ability to adapt to anything new is like a shock to the system. The Dcau wasn't and isn't consistently the best and most serious take on superheros.
It to also had its own tweak on many comic book characters just like other cartoons did and with its potential run of episodes (teen titans, batman, the new batman adventures, batman beyond, zeta project, superman, justice league and justice league unlimted and 6 movies) didn't do everyone their fare share of justice.
There are numerous elements where The batman shows itself to excel in areas where dcau didn't.
One of these would be Bruce's complete ownership of Jone Jones in the Joining, His continual will to stop a criminal in Artifacts, His loyalty to Dick in Matter of the family, and also his relationship with the joker which plays a heavy part in this cartoon.
Also his skills as a mechanic as well as his time outside of the costume is also heavily looked like as well as his relationship with this universes' two face. clayface, where bruce and batman both try their best for ethan, Something not particularly shown with Harvey dent in the animated series.
Now i;m not saying dcau didn't have its good bits but it also had quite a few stinkers and many ordinary mob boss episodes don't stick out on their own.
All in all, maturity is there in the batman if you look for it, just like childish frantics are there in the dcau if you look for them as well.