Sure it does.

/s

It only ruins everything when the game wasn't built up for it or they spend too much time trying to focus on all gameplay experiences like Destiny.

Borderlands, L4D, Payday, Dead Island, Torchlight, Magicka, Castle Crashers, the upcoming Evolve etc...all built up for co-op

While shoving it into games like Dead Space, Resident Evil and yes Mass Effect 3 (could of spent their time making a better ending and finishing off the Omega content which became DLC) end up ruining the game

Because the games feels like it is designed for more than 1 person like Dead Space 3 or MGS Peace Walker. There are more examples but those are the ones i can think off recently. Look i dont mind co op as long as it doesnt interfere if the player want to play and finish the game solo.

Here is someone like you who doesn't realise the time and resources that goes into co-op...especially adding it into a game like this

The franchise was never a co-op game, it was never built up for it meaning they have zero knowledge of building a co-op game from the ground up.

Doing co-op would require a lot of resources as they have to make sure quests, item management, enemies, respawn rates, item drops/rewards, mission structures are equal for both single player and people who are playing with two people.

During this time they could of better off spending it on getting rid of the single player bugs they have OR adding features you'd probably end up getting in DLC.

Not to mention it's Bethesda, they can't even do a single player game without bugs, imagine the bugs co-op would bring. So ontop of their infamous single player bugs you would have co-op ones. They might end up fixing co-op ones first as it would be the main feature for the new game while single player ones are put on the back burner....same goes to exploits.

It's really not that easy and I don't see why for once we can't have a game which is purely enjoyed for it's single player experience. Look what happened when the online went off over Xmas...this is why single player games need to survive and at the minute Bethesda does a good job keeping them alive

"But there isn't anything wrong with people having the option."

You do have an option....go play another co-op game which was actually built around the feature, not wanting it in a game you'll enjoy for a month to show off to your friends, get bored at the half arsed single player then end up going on the next brand new online game

"Blah blah"

Now your just being immature...

Let me guess another know-it-all, who really knows nothing. As history has shown us, you don't shoehorn in features that series inception never included in the first place because it never works. The reason why borderlands works as a co-op game is because it was created with co-op in my mind from the very beginning.

You want a example of how co-op ruined a series, take a BIG LOOK AT "Resident Evil"

@MrSwankSinatra

But But Resident Evil Outbreak

Chances are they're just going to use another modified Gamebryo engine, then call it new to fool people. The thing is, each time people found out it was the same engine.

First of all, they should respect their customers and release the game in a finished state.