I went to the Texans-Titans game two weeks ago. The stadium was 2/3 full. Now Rootes may be referring to the fact that the stadium is sold out. The problem with that analysis is that the overwhelming majority of tickets were sold prior to the onset of the kneeling protests. He can point at that fact, but if there's really a problem, then the Texans and NFL are living off the corpse of a once-great league that is now in decline because of the behavior of both its players and management.
And TV ratings are dropping a bit, but will probably level off.
But the next big sign of trouble will come next spring when season tickets sales are down across the league, as corporations decline to renew.