Okay, I'll give you 12 months. The difference is negligible. The techniques used to root the PS3 are so fundamental and well-known that it was largely a matter of trying them out. There was nothing revolutionary here, it was just a matter of people with sufficient expertise and resources becoming motivated to spend the time to do the necessary work.
The point remains: working with your users diminishes their motivation to work against you. Minimizing the artificial constraints placed on what users can do with the device they purchased means that huge swaths of people who might be motivated to reverse engineer your safeguards won't need to. The community relationship will be improved, new uses for the hardware that you didn't anticipate will be found.
When you can improve sales and customer relations while simultaneously lengthening the lifetime of your product as a DRM device, well, it seems like it would be a relatively simple decision. The net effect is to attract and retain customers both at a consumer and industry level. Consumers get a more versatile device - and equally important, respect. Developers get stronger and longer-lasting DRM and a larger and more robust consumer base. Everybody wins.