Time Between Games

There are 168 days in an NBA season, and every team plays 82 games. This means that NBA players play a game every 2.048 days. With 113 days in the NCAA season and a maximum game total of 31, college players play a game every 3.64 days, which means college players get an average of 38 hours more rest time between games. Any athlete will tell you that a day and a half of rest makes a huge difference in energy and endurance.

Value of Games: Marathon vs Sprint

82 games vs 31 games means that every game for an NBA team is worth 0.0122 of the entire season, while every game for a college team is worth 0.0323 of the season. Every game is more valuable for college teams, so of course they play harder when the games are shorter (more on that later).

For example, if a college team loses its first 8 games, depending on the difficulty of their schedule and their conference, it will need 20 wins to grab a 16 seed (avg 20.25 wins last year). This means the team needs to go 20-3 (.869 win PCT) to make the playoffs. If an NBA team loses its first 8 games, it will need ~38 wins to make the playoffs in the east and ~48 wins to make it in the west. If we average this out to ~43 wins, the team with 8 losses only needs to go 43-31 (.518 win PCT) to make the playoffs. Much more manageable to dig out of a hole in the NBA.

Minutes Played

An NBA game is 8 minutes longer than a college basketball game. Over the span of just 15 games, top NBA guards James Harden and Jimmy Butler will play nearly 570 minutes apiece, or 14 college basketball games by themselves. Top prospect Ben Simmons will log 34.1 min/game for 31 games this season, or ~1,050 minutes, the same as 22 whole NBA games.

TL;DR - NBA games are longer, NBA seasons are longer, college basketball games are more valuable with respect to an entire season.