Well, NoStress, if you "wait out" Delta and standby instead of paying the fee because it is too high (I estimate 4 out of 5 FF's do this, judging from listening to the chatter with agents in the lines I stand in), then Delta simply loses the revenue it might have made with a more modest fee.
As to the bigger picture of the original post, Delta makes the "best" money from me getting my people to buy about $36,000 each in tickets every year and then fly the 100-odd segments in the first place. Adding anxiety on many of those trips home because you wished you could book on an earlier flight that has the space to sell anyway seems out of synch with what a "bundled service" business should be. Why have customers sit in the Crown Room drumming their fingers wondering if the standby will clear, and then clear it anyway (as usually happens)?
These "change fees" are sort of an inverse corrolary to the "upgradeable but you cannot upgrade yet" fares. The fees create the anxiety when finishing the trip; the upgrade stuff creates anxiety when beginning it. Yet usually one will get the standby coming home, and often can get the upgrade starting out. So why play this mind game with the passenger?