I had bad money management in my previous team. Small arena, and being dedicated to training NT players since my first season (it was season 3 then so it was pretty easy to own NT players). Iirc I don't remember when I did not have a 200k salary monster PG on my roster (actually trained two of them up but they weren't at their peak at the same time).
I was barely earning any money so it wasn't that I didn't want to buy players. I just didn't have the money to buy or maintain any new players, and had the money to continue maintaining my old ones, so I didn't really sell anyone.