I guess I can see reasons why some companies may want to be able to produce time-limited drivers: Maybe they want beta versions to stop working, forcing users

I guess I can see reasons why some companies may want to be able to produce time-limited drivers: Maybe they want beta versions to stop working, forcing users to upgrade. For offline computers, it might be that some companies would see this as a way to enforce contract periods (customers would have to install an update to continue using the product when their contract is renewed). Of course, disabling driver signature verification is still a way to bypass that, but often times the companies that do things like this probably aren't thinking about that.