I agree but there are multiple options they could monetise. Extending Firefox Sync and have it sync more types of content. Browser ID could easily be a monetisable service. Reputation systems would be a great fit into browsers. There are many many ideas where Mozilla could make money.
That's not something that will happen.
Mozilla is not there to monetize stuff that way.
They want this stuff to reach everyone. That means free.
If a non-user-impacting thing can bring money (such as the search deal), then great. If its feature that is only available for subscribers - no way - will never happen.
