Social Networks should allow you to follow and comment on profiles on other Social Networks = No Walled Gardens!
We have become so used to being walled into Facebook, Twitter, Google+ etc and we forget that once e-mail had suffered from this and then started interoperating (imagine only being able to e-mail someone on the same server as you) and even instant messaging used interoperate very well (remember Pidgin, Jabber, IRC, etc until Google discontinued Jabber support as did others).
And yes it is quite possible but the big corporates want to own all your data within their own walls.
But as I have been digging around after #deletefacebook I have realised that the independent federated networks do allow such interoperability. An example is shown of my Maston account in the attached photo. You can see my Squeet.me account is following the Mastodon account (far right column I'm viewing that profile), and vice versa. The really interesting bit is that Mastodon is a Twitter type service whilst Squeet.me is a Friendica service similar to Facebook. They are very different but allow interchange. So you can join the one you like and follow anyone anywhere. So you should find that Diaspora, Friendica, GangGo, Hubzilla, Socialhome, Ostatus (and I think GNU Social) will all play together nicely - the way it should be.
I also like that the Friendica network allows you to automatically pull in your posts from Twitter, G+, etc and also to push anything from Friendica out to Twitter, your blog, etc. This makes it easy to do everything from Friendica without losing your legacy mainstream accounts.
More features about Friendica at https://friendi.ca/about/features/.
Some highlights though are:
* Birthday reminders
* Unlimited characters for posts with text formatting
* Likes, and dislikes
* Events with accept / decline
* Notes to self
* Photo albums
* Multiple profiles for different audiences
* Automatically expire old content if you wish
* Fan (one-way) relationships are fully supported
* No paid averts and no sale of information
* Community pages can be created for large special interest groups
So it is really up to us to decide whether we just want to stay in the walled garden, or whether we want to peek over the wall and find others with similar interests elsewhere. There is a whole big world out there and you will likley not hera about it in the mainstream media - as they often only know about someone who has paid to put adverts in their publications.