Maybe part of their thinking is how will bringing up players play into their ability to be competitive every year. You can delay bringing players up by playing players with bad contracts. There have been plenty of them since the La Russa/Lunhow era. And it’s easy to deplete your farm if you only have a few good candidates and what do you do after that?
They make more money this way too, keep a higher attendance from year to year and it works better with their hardcore marketing agenda. The downside is their commitment to winning is farther down the list of priorities.