For me production has never been an issue, and I am frankly surprised by the number of people complaining about it.
Every time I play The Enemy Inside in my car, for example, it just kicks ass, exactly what the song is supposed to do....and I have never had issues with ADTOE or any other DT record.
The only things I really dislike are the snare sound in I&W (but it doesn't have an impact on the music, overall) and the snare sound in Along for the Ride, but is' more a question of tuning rather than production (the same snare works in the other DT12 songs for me).
In addition, there are so many things you can adjust in the sound balancing thanks to the modern technology that you can basically have each record sound the way you like...same for the loudness war issue.
As ususal, de gustibus...but I think it's not correct to say that some modern DT albums have a "bad" production or there was a "downgrade"...while it's fair to say, of course, that some people just don't like it.
It's a matter of taste, not of "professionalism".