I am against multiplayer-only games because they are unplayable if the online community moves on to another game. The older the game is the less functional it becomes, until it is basically worthless. So if this is the inevitable end-result, I say it was worthless from the start and it just took a little while for people to realize it.

It's kind of funny, really.

10 hour single player game -- "I can play it again if I want! Yay! I might play it three times and get 30 hours total! 30 hours makes it completely worth the money!"

Multiplayer game you can put hundreds of hours into -- "Sure, I played this game for 50 hours but what if it gets shut down a year from now? 50 hours of gameplay is a waste of money!"

Well of course I'm biased against them because I prefer single player games by a large margin over multiplayer only games. Indeed the only multiplayer only games I will ever play are the free ones. And indeed with the rise in multiplayer-centric gaming arguably single-player content has suffered. Why is this not an acceptable argument against them AAA priced multiplayer only games? The way I see it those MP only games are hurting the thing I like most about video games.

Was I excited for SW Battlefront? Hell yes I was excited. Then the news of it being $60 MP only killed off any measure of excitement I had.

Except hardly anyone pours that much time into a game, let alone complete them ... 

Shallow example ...

Most people who buy multi-player games put a bunch of hours into them.  I think it's safe to say that they put far more time into multi-player than single-player when a game has both.  Average play-time for Destiny, as an example, is around 100 hours.  You'd have to be someone who doesn't like multi-player to put less--but then, why would you buy a multi-player game in that case?  

The simple fact of the matter is that multi-player gamers usually get a lot of value out of a game, even with the whole "but it might shut down in a few years" qualification.  That they get that value up front rather than on a replay five years from now doesn't matter.  

I don't mind them. I just don't buy them. I only buy games that has a SP.

MP only just isn't for everyone, but I say more power to the people that do like it.
Obviously the people that dont want to play MP or dont play it a lot will make comments like you mentioned because FOR THEM a price tag of $60 isn't justfied, that doesn't imply to everyone.

Theres a market for all kinds of games, including MP only, world of warcraft more then proves you dont need single player or a cheap price point to get people excited, lol

Star Wars Battlefront was a complete waste of a licence. Imagine if it was a huge RPG set in a vast universe in the vain of the Mass Effect games. Instead we got the usual bland shooty shooty dressed up in pretty graphics.

I get bored with the MP content of games, so i rarely play them. I won't bother to buy a game unless it has a single player story mode.

I think the bias exists because of factors many have already listed. I mean, (while a long time off) servers could be turned off making the game useless, community dies making getting into games or enjoying yourself in it also dwindle, sometimes there is a distinct lack of content to keep someone interested etc.

My main gripe is the idea that these developers spent time creating the gameplay don't put it into a well thought out campaign and stuff and have to spent no effort in creating AI for opposing characters in said campaign. It saves they loads of time no doubt.