The protests and injuries such as concussions don't affect my viewership, what does however is ....
Thursday night football ... I work til 9 on Thursdays so it's generally about halftime when I get home and I mostly don't bother turning the game on.
When the Bills aren't playing the 1:00 game on Sunday I find I'm either golfing or watching NASCAR instead of watching other NFL games.
I'm so sick of the patriots that I'll only watch them when they play the Bills. Thurs, Sun, Mon night I won't watch if they're on, and last years Super Bowl I skipped for the first time in 45 years. I had zero interest in watching them win another Lombardi.
Too many penalties are making games difficult to watch. Biased officiating is infuriating as is poor officiating. The two Walts and Hochuli need to be retired.
Too many teams relocating. If the Bills left Buffalo, I'd probably quit on the NFL and just watch college. Syracuse University will never leave Syracuse etc ... I could easily see fans in Oakland, St Louis and San Diego losing interest.
Too many games held out of the country. This year they had 4 or 5 games in London and are having one in Mexico City.