That is an excellent point my friend.
Look, its human nature to do just what is required and nothing else.
At UT, if a professor said "today's lecture will be covered on the exam", guess what? Everybody took notes and it was so quiet you could hear a mouse fart, LOL!!!
If a topic was not going to be on the exam, everybody spent the whole lecture on their phones, laptops, ect...
At work, I manage a division at a factory, guess what happens when the division meets its quota for the month and its like the 28th day of the month? For the next 3 days, nobody does jack. People call in sick left and right, the ones who do show up take a break like every 15 mins, everybody is in the hallways talking and telling jokes, guys are bragging about who they are going to be banging on the weekend, ect...
The Cowboys are no different. They get the highest ratings in the league, they get the most prime time games of any team, and the players get paid like they are the best at their position in the league, and all of this happens despite not winning anything besides a division title every other year or a wildcard game every couple of years.
Bottom line, be it in school, at a factory, or on a football field, people will do the bare minimum to get by, that is just human nature.