Playoff basketball only has the best teams and the best players. The play is at the highest level possible for the sport, and you do not need to write drama with the storylines that are present. Will an aging veteran win a ring? Will the young guns take down an established team? Can the young Chosen One actually win the title and maybe earn the non-stop buttkissing that he receives? It is far more entertaining than your average tv show.
I know the league has an image problem and people blame it on demographics, but I do not buy that. The NFL has a huge black presence, and yet, Americans watch it non-stop. I think the NBA just has too long of a regular season and too many teams. If the NBA had 4 fewer teams, every team remaining would be 2-3 players deeper, meaning that the talent wouldn't be spread so thin. The league will not contract though because the players union would fight it tooth and nail. In a perfect world, the NBA would be the 1980s forever.