What you don't understand is that it's not just Sony's call....it's up to the movie studios. Did you think Gates wanted so much video copy-protection in Windows Vista? MS pretty much had to put it all in, otherwise the studios wouldn't give him the rights for hi-def video playback on computers. Imagine not having HD-DVD and Blu-Ray playback on the newest OS. Talk about a killer-app.
If the studios find out a player is compromised, and they tell Sony to pull the plug on that model, Sony has to comply. (I know Sony is one of the "Studios", but they aren't the only one.) Future player updates will be mandatory for new keys, and it is the consumer that will have to pay for them. There are echoes of DIVX here.
This is a prime component of Blu-Ray's copy-protection. They touted this as a major advantage. If they don't enforce it, then it's no better than HD-DVD's.