I think the trend, which is strongly encouraged by various sites, to get people to "like" other people's comments, as on Facebook, is an insidious one.
It shouldn't matter if hundreds of people agree with, or like, what you say or nobody does. However, it has been known for some Gransnetters to express concern as to the lack of response to a thread they have started or a post they have made. It's not a competition but, in my opinion, this sort of affirmation process turns it into one and encourages a sort of "group think" mentality.