Seems like it's just one more way for browser makers to control and collect what we do online. It's not the browser makers responsibility to be parents and keep their kids er users safe. Overreaching vs responsibility, education and common sense.
Pro users like ourselves don't need this. Mozilla has gone the same way as Google with Chrome and Opera...not much different at this rate acting all big brother on us as if they know better than we do and have no control over 'features' like this anymore.
Atleast I found a way to get around Click-to-Play so to speak. I just open Blocklist.xml and remove everything under the "Pluginitems" section.
As therube pointed out above with »kb.mozillazine.org/Blocklist.xml
you can also turn off updating that it does once a day and enter the updates you want from the list online.
This is what Pro users like ourselves and Corporate customers using the ESR releases need to get around this and take back control.