Because when we give awards for everything, awards cease to matter.
To be fair football makes their "regular season" a huge trophy, and they have cup competitions as well. But yeah the history and system of American sports really isn't regular season friendly, I'm not in favour of the proposed changes
If NBA fans desire a league where winning a playoff tournament is important you're not going to be able to have a league where the regular season is vitally important when over half the teams make the playoffs. But you can't just drastically reduce the number of teams that make the playoffs, as now none of these teams have anything to play for and would lose a lot of money. You have to give something meaningful to incentivize the teams that know they can't win the regular season. This is where the benefit of having multiple, smaller national leagues roughly equivalent to each other massively helps European soccer succeed with the league structure they do. You can be anywhere from 4th to 6th best and still make the 'playoffs' (either the CL or whatever they call the lesser version of it these days).
The reality is that most European soccer teams have zero chance of ever winning a league title and all they really have to play for is the chance to make one of the playoff 'leagues' (and the money/pride that comes with it), or avoid relegation. So in a certain sense, it's not really that different than North American sports leagues, just that their conferences are called leagues and are completely separate from each other (somewhat how football and baseball used to be prior to the AFL-NFL merger / Super Bowl era and MLB inter-league play).
So maybe that is the answer, have the NBA go to a system where teams from the Eastern and Western conferences don't play each other and the winner of each conference (based solely on the regular-season) faces the other for the championship, just like football and baseball used to be many years ago. To make up for the lost money from playoff games, all other teams from both conferences can play in a single tournament of their own for a lesser trophy (possibly stealing from the home-away aggregate score format of early rounds of the CL).
Personally, I don't see a need to make such radical changes, and I don't think there is an overwhelming appetite for it among fans of NA sports leagues.