This is just my opinion but I think Goodell, in the long run, will be exposed as an awful commissioner. His missteps on concussions, Ray Rice and others aside, his obsession with expanding the NFL to Europe and even Asia is eventually going to turn off the fan base in the US. There is such a thing as over exposure and Goodell is taking the NFL in that direction. I also think he has not paid enough attention to the quality of product we see on the field. I don't think the line has been crossed yet, but as the rights to broadcast the NFL get more and more expensive, those companies that bid on the rights will need to see more revenue opportunities - more commercial time. As it is games are getting longer in duration. Consider this fact, there is less than 10 minutes of action in a football game which is about 4% of the game duration. How much worse can this ratio get before fans start changing the channel?
Everything the NFL does not has become a spectacle. The draft, and even the release of the schedule, are all treated like main events. There is a straw that will break the camels back, even for the NFL.
Other sports once enjoyed great popularity, even tennis was once a hugely popular sport in the US. Bowling was big in the 60s but now you can barely find a live bowling event televised. Remember too, baseball was once the most popular sport before it faded. The NFL is not immune to the same falling popularity as other sports and I think Goodell is definitely heading in that direction for a slew of reasons.
I admit I am not a Goodell fan. I think he is controlled by a few powerful owners. That's great for their teams but for the rest of the league its not so great.