The root cause is still that there are too many meaningless regular season games. The owners and players won't reduce the number of games due to the loss of revenue, so this is the situation we're in. Silver and Dumars (representative of the owners) are trying to put a good face on it because they're in the middle of a TV negotiation (along with their gambling partnerships) and load management has started to negatively impact the product. As a group, of course the owners want stars to play more, but individually they want their own teams to win. That's why they need it to be fairly applied across the league that resting won't get too extreme.
It's also a question of what kind of league you want it to be. Making the regular season more important would mean younger players increase in value. Keeping the regular season less important and keeping this current playoff system means older players have a better shot at still being there in the end. For example, I don't think LeBron is a serious title-threatening number one anymore due to his age. However, the league can still viably market him as one because a team like the Lakers can fumble around the regular season, make some good trades, then win two playoff series and appear like they have a shot when actually it's very unlikely.
The OP also is forgetting about modern surgical procedures that have made longer careers more possible. It used to be the case that certain injuries just hampered you for the rest of your career. Players can now come back from serious injuries, and the league increasing in size means there are more teams where these older guys can be the "star" on a bad team. For example, guys like Rozier and Hayward can be "stars" and paid big money to be on a bad team, but they'd probably be bench guys on good teams.