It's hard to say if G+ long-term game is brilliant. Although its easy to say Android and Chrome are obvious longterm winners.
G+ still seems forced down our throats. It's the only google product that I've felt forced to use. Just goes to show you how desperate google is to get involved in the social game. We willingly use Chrome, Google, gmail, and android because they are great products.
I still don't think G+ offers something in social that we don't already have. Though G+ is a nice product. Ultimately I think it will find its niche and never become as big as Facebook.
I've been using Google for many years and never had this happen.
I'm not sure what you mean by a different account for each service removes the benefits. At this point all of the services I use are under one account - my main email address. They are all nicely integrated.
My only complaint is that I can't alias all of my other email addresses off the main one, having a "single Google identity". So - if someone else uses one of my other email addresses to share a doc with me, I have to either logout/login or re-request the share using the doc I want (which is the path I use).
Chrome sync is incredibly underrated in my opinion. I've got my browsing history, bookmarks, Chrome apps and open tabs from my work and home desktops, my laptop and my phone all together seamlessly.
In what way is it superior to Firefox sync, for example?
Personally, I don't want my work PC cluttered with random bookmarks from leisurely browsing at home - and if I did, I'd put them on Wuala, where my stuff is client side encrypted (FF claims that too by the way).
People locking themselves into one service provider for everything voluntarily, being completely dependent on it, subsequently missing out on better alternatives outside that walled garden until it blows up.
I think our definitions of "service provider" and "walled gardens" are different. There's nothing about Google that prevents me from using any service that I want and even thought they are integrating many things in more tightly, I still have an incredible range of motion for things outside G+, as well as integrated with it.
I know this is a religious argument - I've tangled with it 9,341,759 times over the years. No one ever wins it - time is the grand determinant.