Sorry you do understand the NBA well!
I agree the game is guard dominated in that they don't allow near the hand checking they used to so it's easier to get into the lane.
I think some of the lack of post game is just a part of evolution. Maybe it was the euro's that lead the way showing that you can space the floor better with 6'10 guys who can put the ball on the floor and have 18 foot plus range on jump shots. This lead to young players who are taller to work on that part of their game more than pure post stuff. I think sometimes big kids did not not want to get forced to play the post just because they were tall and it helps when they see big guys at the highest level who have more than just a post game. I think it's just evolution of the game more than anything.
I mean NBA teams don't want to waste roster space on straight up goons any more. It seems like you saw a bunch of players like that around the NBA in the 80's especially. They were not good players but they used their 6 fouls to just hammer anyone who tried to get to the hoop via the lane.
I don't see it as players being less skilled now because they don't have back to the basket game I consider today's player way more skilled.
The funny thing is when I watch NBA games from the 1988 - 1994 time frame which really does not feel that long ago I look at players and they look like a joke. They are just so skinny looking compared to today's NBA player.
Guys have gotten bigger, stronger and faster and I guess I feel that they have actually improved upon their overall game.
I agree with you that the post game seems to be the part of the game that players seem to not work on as much anymore. I think they still allow a lot of contact on the blocks so maybe some players feel shooting an open 15 foot shot is a better shot than trying to bang your way through heavy contact to shoot a shot around the block area.