Which they would be doing anyway if FB didn't exist. FB to them is convenience, nothing more. Many of them probably think that FB is "the Internet", just as many AOL users thought that in the 90's. They are only "connected" inside the walled garden; they have no idea of all the things that are outside it.
Yes, it is a convenience... Much like email is a convenience over snail mail and Face Time is a convenience over meeting in person. Arguably the car is a "convenience" over the horse.
Discounting the breakthrough in technology that spawned the term "social networking" doesn't really help your position.
AOL may be a defunct company but in their hey day they brought millions of people online. They deserve more than your mockery.
And that is relevant how, exactly? Even if it was: 6B people are NOT using it.
Show me a service that's connected more people that hasn't been around for more than 20 years and not named "the Internet."
The greatest value FB brings is making it easier to connect and share (ie. be open) with others and 1B people derive enough value in that to come back on a regular basis. That's the point.