I can think of a few reasons:
- They are very quarterly-results-focussed
Everyone is swimming in pain today, so taking some losses isn't going to look too bad, especially if it means getting back to business next quarter. Let's face it: for a lot of the players who got giddy about the prospect of free profit, the come-down has been hard: it was Musical Chairs with not too many chairs. So: this is a way to close a bad chapter.
- The assets might get worse!
Who knows what's coming next? These pools are still subject to defaults until they are completely paid-out.
- Loss provisions can eat up your capital base
If you believe that holding onto the bad stuff is keeping you from taking advantage of some of the opportunities out there, getting out from under this stuff is a way out. You might actually get someone to bid more than you think they are worth, so you'd get some of your reserves back, too.
/jordan