If the objective of the organization is to win a championship, and resting players during the season increases their odds of winning that championship, then there is logic behind doing it.

If the objective of the team is profit maximization, then the equation is a little more complex, but is still not at odds with load management. From some work I did years ago with an NBA team, the single biggest factor in putting butts in seats during the season is having a team that will have a shot for a championship (i.e. the team makes the playoffs). Consistently making the playoffs, increases the number of butts in seats by an increasing amount (with some decreasing returns). The more butts in seats, the higher the revenue, and costs are relatively fixed (player salaries being the single biggest cost), so more tickets sold = higher revenue and profit.

However, the second biggest factor in selling tickets is whether the team has a marquee player that people want to come and watch. It generally has to be a super-star to make a sustained difference. Some simple examples that jumped out of the data when I did this work (dating the work here) were Kevin Garnett, Allen Iverson and Shaquille O'Neal (amongst others). So, if you rest those superstars in your quest to meet a championship objective, you will have a negative impact on attendance, and hence, revenue.

The two have to be balanced, but there is an economic case that can be made that using load management in an appropriate fashion is actually what the fans want---balancing potential to win a championship with ability to see favorite players in action.

A better question might be, "is the NBA season too long?". If the schedule were to be reduced by 10 games a year, would it give players the rest they seem to desire and eliminate the need for load management? It would obviously reduce the total inventory of games, which means that the supply of tickets would be reduced. For teams in a position to increase prices (i.e. good teams) because they are already selling out, or are close to selling out, their arena, this approach could keep them revenue/profit neutral, or even increase that. For teams that are already struggling with attendance, maybe this would be a bad option.

But, the concept is one that I'm sure teams are analyzing from multiple perspectives. There are a lot of smart people today in the front offices, and I'm sure these decisions aren't made without some meaningful analysis (and maybe a little push/threat from agents like Scott Boras).