Because they had to make an effing Vita game! If they'd made a full-blooded PS3 game and it had bombed I'd have accepted the need to close them. But I'll never not be salty about them being closed after having to make a game for a paltform that Sony itself made dead on arrival.
Liverpool were suffering problems in 2010 following the release of Wipeout hd in 2008 and it's expansion in 2009.
They wouldn't have had the staff or resources to commit to a new console Wipeout after the restructuring, and they themselves have publicly mentioned how vita development was easier to do.
The reality is that they were either given the vita project or just shut down with the Wipeout hd expansion being their final release.
They werent financially viable for years, and that is why they were shut down.