While Batman: Year One is extremely faithful to the source material, your claim that Bruce Timm, Lauren Montgomery, Sam Liu, Christopher Drake and the cast put no real thought or passion into Batman: Year One is inaccurate.
While Batman: Year One is extremely faithful to the source material, you felt no real passion for it watching it as a Batman film likely because, as Bruce Timm said, "It's really not a big spectacular action adventure thing with lots of special effects and explosions. It's a very intimate story. Put in more gadgets and the flasher cars, and then suddenly it's not Batman: Year One anymore."
http://www.mtv.com/videos/interview/670500/sdcc-2011-bruce-timm-on-batman-year-one.jhtml#id=1667825
As Bruce Timm explained, "The Dark Knight Returns is so big and operatic and Batman: Year One is so personal and small scale. It's almost like if The Dark Knight Returns is Led Zeppelin then Batman: Year One is like Chet Baker or something. There's that big of a difference between them."
http://voices.yahoo.com/frank-millers-batman-year-one-being-adapted-into-animated-7945562.html
While Batman: The Dark Knight Returns is also extremely faithful to the source material, you feel Dark Knight Returns Part 1 and Part 2 improved on the source material because you likely felt engaged and swept away by the storyline for the first time watching the Part 1 and Part 2 films, and you likely never really enjoyed reading the Dark Knight Returns storyline in the graphic novel due likely to negative preconceived notions of Frank Miller hating Superman, etc.