Yes, it's a stretch to believe that UEFA is objecting strictly on a point of principle.

UEFA seems to think people have forgotten that they tried to buy off top teams from the national organizations into a European super league.

In effect they did it anyway with CL.

The super league wasn't UEFA's doing at all. The top clubs themselves tried to break away and self-organize, and they ultimately won some concessions from UEFA (new CL format, more CL money to the big teams)