So far as I can tell, Facebook offers no significant expertise on techie computer, smart phone, tablet, etc. problems. Sure there is a little help for Apple newbies. And some links exist there for help beyond Facebook. But Apple troubleshooting matters are a very minor part of Facebook.
As for an umbrella website to help Apple users get help, with a single registration, by accessing any of the various single purpose Apple help sites, it's a nice idea but it requires cooperation from all the Apple websites --doesn't it? And the cost has to be shared, doesn't it? I'm not sure that the cooperation or the willingness to share costs will be there. And I'm not sure that FTM would do that well in that environment. How does FTM stand out? In numbers, no. In talent maybe -- but who knows that? In special treatment of users. Maybe. But who knows that? In special attention to a certain class of users. What class? FTM is a general all purpose help site. It has not gone to any specialization.
I think that FTM has to do a better job by itself of gaining users. And to me that means getting itself mentioned more often (and favourably) on Google and Yahoo and getting itself on some of the social media sites. And it has to explain why it is a good choice compared to its competitors. And that is not an easy task. Word of mouth works, but now there are not enough mouths at FTM to do that work.
Ships can be righted, but it's usually not that clear at the outset how to do it.
