According to what you posted, divisions matter more in baseball and yet no one cares about their regular season either. People are just throwing their own preferences/gripes out there. You really think the average fan cares about divisions? You think the average person that isn't watching NBA games would start watching if there were more divisional matchups of teams they clearly don't care about anyway? No matter how you slice it, you just can't compare 16 games on a set day (well sorta) on the weekend, in the day time or prime time at the latest with white men as the glamour boys to 82 games throughout the week usually at night and often late as fukk if you live on the East Coast with a bunch of black men running shyt.
Baseball fans care a great deal about their teams regular season and division. Baseball does very well regionally because of that.
Baseball's problem is there's too many games to maintain a consistent national audience during the regular season. But I suspect they're happy with the tradeoff as it hasn't hurt their national audiences when the postseason starts.
And yeah it wouldn't hurt the NBA to have more division games. You don't even have to take away the marquee national games to do so.
The question of would it draw the average person who doesn't watch NBA games is the wrong question and isn't your target audience.
Your target audience are the people who wait until the playoffs start before watching. Because that's when things are at stake.
You have to create stakes for the regular season (as best you can, no league is the NFL) more division games would help do that.
Bottom line, there's a more meaningful NBA regular season to be made and it involves division rivalries.