This question struck my mind when a short discussion about this topic was brought up in #SGAnimeBloggers.
I can only think of a few reasons why.
First, you like the Anime series. Taking myself as an example, I only watch series that are of interest to me. I find that if I want to waste spend my time on anime, I might as well make the best out of it and only watch anime that I would enjoy. This might mean not watching popular anime that everyone has been ranting about. I see no point in just following the crowd, when deep down within, I am just watching not for my personal enjoyment but to be able to keep up with what everybody is currently discussing. This would defeat the purpose of watching anime, and the true meaning of being an anime fan. It would be like chasing trends, like what many teens do.
And this brings us to the second point. Some people watch anime series that are popular so as to keep up with the anime community. Majority of the anime community are made up of casual watchers who watch mainly only shonen anime, and this group watches anime for the following reason. An example would be as such.
A : “Hey, do you watch DGrayMan? Allen Walker is so totally cool….. blah blah ….”
B : “Sorry, I have no idea what is that you speak of.”
A: “DIE IDIOT!”
Ok that was a stupid example. I dropped DGrayMan at episode 15 LOL. Anyway, you can roughly understand what I’m trying to say. Some would be influenced under peer pressure to watch an anime which just not appeal to them, just because they want to prevent the situation above from happening to them.
Also, since so many people out there watch anime, it’s easier to start or continue a conversation if you have some knowledge about popular anime, if you happen to run out of topics. That, however, should only be used as a backup plan.
Lastly, people watch anime because they have nothing better to do. They have completed hours and hours of drama, and are sick of watching real humans on the screen, and they have discovered anime, a fresh new type of media for them to splurge their time on. I have nothing that I can say about people who watch for this reason, because not even words can describe it. Fortunately, these people are the minority.
Personally, I think I watch anime for the first reason. Sometimes however, some of the popular anime happen to be the ones which I am interested in. Some popular anime which I did not pick up due to them not being of any interest to me are Kanon and Clannad. Sure, some people may criticize me as a fool for missing out on the greatness of this anime, but I am absolutely sure that an anime is as great as you perceive it to be.
I’m sure many of the anime fans who support the anime industry also watch for the first reason too. In fact, I hope that majority, if not all, anime fans watch for the first reason. The second and third reason are totally pointless, and you would be better off having fun slitting your wrists. After all, isn’t slitting wrists the IN thing now?
Personal opinion > General opinion, when it comes to the topic of anime. Do not have your opinions sway just because they differ from the general opinion. Else, you would be watching anime not for your own sake and enjoyment, but for the sake of others. What good is there in doing that?

The problem is there’s just too much anime to watch these days.
True. That’s why I watch selectively. Only the ones I enjoy. I don’t have all the time in the world to cover everything. In fact, no one has.
Watch a bit of everything then slowly omit them.
Hmm..I start watching Anime quite late…I can’t find few of the anime series that is Interesting yet too old….
but I watch almost anythings. Different Anime have different feeling to me.
@Zero: You are right…there is just too much…
hmmm… I wanna quit watching anime[but couldn't as this is one of the phase of our lives where it won't come back as we get older, might as well enjoy it for awhile]. what i’m sure of not quitting is reading manga and collecting merchandise.
samejima > Don’t quit. Especially if you really enjoy it. After all, Life’s short.
yeah yer rite. I may be quitting anime anytime I want but not merchandise collecting, that’s for sure.
I watch anime coz its teh superiorz to most local entertainment duhz.
Of course, most normal people can’t handle this fact so I don’t go around preaching it.
lol. i got tired of watching the anime just because i’m lazy and impatient. lazy to buy the videos and can’t wait long enough for the videos to load online.
normally i’d check out the synopsis and bits of the anime before watching. The other thing is the art style. The drawings or so whatever you wanna call them is most important.
(actually, i don’t really give a damn about the story as long as i can get some drawing tips from watching it) such example : vampire knight-read the manga, loved the art and storyline. i watched the anime and compared it. UGH!
those animes that are uber long are what pisses me…
i dropped D.Gray Man and Shakugan no Shana because i couldn’t keep up.
yeah..anime is highly addicting. but sometimes you snap because of it.
how can one stand it? the anime tends to be different than the manga. unless it’s been “improved” in artwork. :/
at 1st I only watch anime because of my brother…….. but as time goes by……… I began to love anime…………..