Why do people have backlogs? Honest question, pls read before posting!!

[sergiodaly]

for me its time... and the fact that i am a slow gamer... i always exceed the time of a standard play trough. also, like to collect all the trophies and do some weird unlocks some games have... i buy games, almost every time on sale, so i am not a big spender, but the games do pile up... PS+ is killing me too, several good games per month and only time to finish one :(