Go to any of the forums and read about people with LB7's having warranty claims denied and how the people bad mouth GM because they didn't get injectors because of a tuner being installed. Theres plenty of cases of people putting in a PPE hot +2 and frying the trans and crying when GM wouldn't rebuild it when they checked the ECM trace files and found the tune being installed. There are LOTS of owners of ALL brands of trucks who mod there trucks and then bad mouth the manufacturers when they won't fix them when they see there 5" exhaust covered in soot, bald tires with rubber all over the fenders from burnouts, air intakes, or they can see the power boxes stacked i nthere trucks still. It's happening with all of them, so I can't really blame GM for blocking the ECM, but I do agree it is a "gay move". If I had just bought a $60K truck and wanted to tune it but couldn't because of the manufacturer blocking it I would be upset too.
Mods, feel free to close this thread as I know you don't want this one to end up like the last LML tuning discussion. I was just throwing out an idea that came to my mind.