Any idiot can set up a profile and then proceed to publish utter nonsense and many do but it will get them absolutely nowhere. For a profile to be successful and to be noticed by Google it will need many followers and answers to intelligent posts. No doubt Google will rate any answers you get by the authority of the person who makes comments as well.
Take a look at some of the attempts at spamming on Google+, no one is interested in them, many get their account disabled because there is a simple way of reporting these people and those that do post dribble, and there is a lot of it, normally complain that Google+ is a ghost town because no one ever replies to them. It will do them no good at all regarding manipulating search results.
Google has got this tied up pretty well, true they want as much data as possible from you but you only have to give as much as YOU want to. This is the way Google is going, if you do not like it you do not have to participate but stop complaining, Google is a free service so you are not a customer.