You may be under the assumption that people, whom you circle, should circle you back. It´s time to rethink and understand the nature of Google+
Let me explain: We are not what we like.
- I like cooking - but - I don´t post recipes
- I like urban planing - but - I´m not an architect
- I like 3D animations - but - I have no idea how to use 3D software
- I like amazing nature shots - but - I rarely post any nature photos
As you can see: what I like is totally different from what I post.
As a result it is totally normal that the people I follow and the people who follow me are mostly not the same people.
This may still seem like a paradox to you. So let me explain further.
Real friends are a mutual relation. G+ on the other hand is in large parts not about friends, it is about sharing your ideas, thoughts and creations. As a result the people who follow you are not your friends but your community. Look at it this way: Madonna may sing for you and others at her concert, but would you expect her to listen to your singing? Probably not!
The same is true for Google+ it´s a non-mutual network.
One more thing - This is also about quality: If you follow everyone back, like you are forced to do on Facebook, your stream will fill up with stuff you don´t want to see.
Change your understanding of G+ and see it as a open source exchange: You may not follow everyone back, but in exchange you comment and +1 stuff you like on streams from people that may not follow you. So instead of a digital cock comparison, you end up with quality distribution - and that is what G+ is all about.
This is also written in context of the new Uncircle Chrome Plug-in: http://goo.gl/YD8sN
