If the Astros just swapped Oswalt and $11MM for Happ, Gose and Villar, they have been officially anally raped without lube.
It's certainly a disappointing outcome, but that's the breaks of having no trade leverage and a lose-lose contract situation.
By all accounts, the Phillies were the only team that remained even moderately interested in Roy O. based on the salary implications, and it made no sense to keep him on the roster and dump another ~$20MM+ into a single player when the team is fundamentally incapable of playing competitive baseball for the foreseeable future.
The organization is a no-win situation right now, and the smart (albeit painful) decision was to take the financial hit on Oswalt and try and get back whatever else was available in the way of prospects. Unfortunately, there was only one team who was willing truly willing to play ball here, so no one should be surprised with what the team ultimately received in return, including the money that had to be eaten...there was no other realistic option.
If Roy O. was an impending FA the situation would have been different, but that $16MM + buyout aren't going anywhere, and there's no legitimate reason to believe that the trade options would've been any more desirable if the team waited until this Winter to dump him...especially given the risk of injury and/or late-season struggles. The notion of getting anything better than .40 on the dollar was just not realistic under the current circumstances.
I personally am relieved that this chapter is finally done and an actual rebuilding initiative appears to be in progress.