You aren't noticing something? Look at the amout of friends you have.
Did that? Good. Now tell me how many of those have been inactive for atleast 1-2 years.
But that's not all, of all the hundreds of active people left, with how many do you actually ACTIVELY play with?
What I want to ask, how many people of your friendlist have been inactive since '11/'12 and with how many of those that are left do you actually actively talk to/play with/derp around with?
Of my ~200, around half of them were inactive and I only played with +70 of them one single time. I only play actively with 19 of those.
Virtual world has its limits.