Even if it's not, Sony could have sold unlocked* units at a non-lossmaking value, which would have instantly discouraged a large proportion of the hacking movement. This is what OtherOS provided: a valve for homebrew enthusiasts, why there were no serious efforts for the duration.
*By unlocked I mean "homebrew unlocked" and without the ability to play games.
*By unlocked I mean "homebrew unlocked" and without the ability to play games.