why don't the NBA owners bring in replacement players?

Because they are gods, not just athletes. Stop thinking about why and just help support the rich. Ticket prices cannot drop. The owners actually do not have enough money yet. Work hard and punish your body for the little money we make and be happy to pay any price for tickets/merchandise.

In my opinion the NBA should hire replacement players. The sport has expanded worldwide, and there are many players on other teams outside the US that would be likely more than happy to jump to the NBA. There is also new players from college coming out each year as you pointed out, plus there would be players that now with the union decertifying, that would likely cross the so called picket line. I root for my team, not for the individual players when I watch basketball. Like any other team sport, it is the team not the individuals that win games. In fact it is the large egos of the so called current top basketball players that has turned me against watching more basketball. I expect this is true of many other fans and why so many rooted for the Mavericks to beat the Heat this past year.

A lot of reasons why you dont bring in replacement players...1) Everyone who wants to be in the NBA is already there...2) nobody is going to watch replacement players and 3) no owner is going to want to pay replacement players...they barely want to pay their current players

I'd rather see replacement players. That would be fun! I'd actually buy tickets.