I have a social networking account already, thanks.
I have an email account already, thanks
I have a cloud storage account already, thanks.
I have a search engine already, thanks.
I have an instant messenger already, thanks.
When you try to do EVERYTHING, you believe that all your customers will drop everything they have years invested in and run to you. Doesn't work out that way. And if you get over-precious and try to force them to do it, well, that doesn't go down well either.
So run them as separate, independent services that I *can* join together if I want to (it's handy to be able to sign into Google Drive with my old GMail account, for example, but don't FORCE that upon me).
In the same way that if you sell me TV, phone, Internet, water, gas, electricity, burglar alarm and music lessons - and then try to "punish" me for not using one of them, or force me to use one in order to get another - chances are that I won't use any of them. Whereas if you just ran them all as separate services, I might well decide to lump in TV, phone and Internet into a single package for convenience. But you have to think about what happens when I'm perfectly happy with my Internet provider and DO NOT want to change. If your offerings are that inflexible that you won't let me use one without the others - even if the others are useless to me - then I'm likely to find yet-another-company that will do, say, my email without requiring me to sign up to their social network too.
This is exactly how I viewed things. I was one of the first GMail accounts, back when they were invite-only and nobody knew they existed. It took over from my Hotmail (primarily because my Hotmail account was trying to tie into my Windows Live account, and into my Microsoft account, etc. etc. etc.). And when G+ came along, I looked and deliberately decided against it. The more the pushed, to more I ignored.
It never got to the point where it became a hassle to opt-out, even when it did become annoying, so I'm still on GMail but not G+. Hence, it's not a shock to me that probably a lot of other people did exactly the same.
Just because you offer "your" Facebook, doesn't mean I'll immediately move everything off my Facebook to change to you. No matter how good you are.