As a corporate sysadmin, I should say that the Chrome method is much better than the Firefox one.
We often have slightly out of date plugins, simply because it takes a while to get new versions tested and rolled out. When Firefox blocks them it breaks functionality and can cause a few awkward problems. Generally that just means that the user will use IE instead, so the protection is lost.
I wasn't aware the blocking worked that way in Firefox. We considered going that route as well, but in our testing the optional block was nearly as effective as fully disabling.
We often have slightly out of date plugins, simply because it takes a while to get new versions tested and rolled out. When Firefox blocks them it breaks functionality and can cause a few awkward problems. Generally that just means that the user will use IE instead, so the protection is lost.