I am not a kit manufacture, but I don't know that I agree that increasing the concentration equates to a drop in quality in kits. It's just a change.
and just my $0.02, so take it for what it's worth.
Depending on the kit I'm working with, I may agree or disagree with your position. I made Selection Estate series kits, and the Eclipse kits were definitely an improvement across the board. Since the private reserve version launched, I have made the Stag's Leap merlot, Lodi ranch cab, Lodi Zin, nebbiolo, and supertuscan and have had mixed results. Although none are properly aged, some results are :
All started 10 (.01)points lower in SG,
The merlot and the cab are lacking colour, and the cab appears to be a dud,
The Zin and nebbiolo are going to be really good, and have great color,
The supertuscan was fermenting in the bag, so that's a "luck of the draw" I've never had before (not stabilized yet). It has been an odd experiment.
I also made a reserve Malbec, but I added a kg of Saskatoon berries (you might call them juneberries) so can't compare to anything. It's quite tasty!
The experiment continues!