I was browsing the web and came across the PC Gamer review of The Elder Scrolls Online. And what struck me about the review was the following paragraphs:

One of The Elder Scrolls Online's biggest weaknesses as an MMO is that it often becomes a worse game when large numbers of players are involved in the same activity. While questing in the High Rock area of Stormhaven I was directed to a monastery that was under attack by bandits. I was given two quests: put out six fires, and deliver healing to four injured monks. Credit for completing these objectives is only granted to the player that performs them, which means that I was put in indirect competition with every other player in the area—and given the linear nature of the game's zone, that means a lot of other people. The monastery might have been on fire, but there weren't enough fires for everybody: which meant hanging around waiting for fires to respawn so that I could get the credit for putting them out. Badly-designed quests like this one are common, and even when your objective is more deftly constructed you are always aware of the conga-line of players waiting to do the exact same thing that you are doing. This takes the game to some strange places: I'll never forget the time I traveled back in time in the guise of an ancient warrior only to find a room full of doppelgangers jumping about, dancing, and waiting for a boss to spawn. Immersive it isn't.

Don't get me wrong, I don't think this is a particular weakness of The Elder Scrolls Online. I pretty much had the same experience in my Wildstar beta weekends: Wildstar has a feature called challenges. The first time you kill a certain type of mob in a area or click on a certain type of item, you get a loud "Challenge begins!" message, telling you that you should now kill X of those monsters or click on Y of those items within a time limit. Sometimes there are several levels possible, with numbers displayed on how many monsters/items you need for bronze, silver, and gold level. And rewards for those challenges are good, for example bags, gear, or crafting resources. But these challenges are obviously designed so that you can achieve them IF, and only if, you are the only player in the area. If you start the challenge and then realize that another player is also doing it, you'll both fail, or at best get bronze.

I consider that to be extremely bad game design for a massively multiplayer game. What those challenges teach the players is that other players are the enemy, who make you fail your challenges. With the timed challenges of Wildstar the effect is especially harsh, because you get an actual "You failed!" message shouted at you. But of course outside challenges Wildstar has exactly the same problems as mentioned by PC Gamer above: Players compete for mob or resource spawns, and it breaks immersion if you are one of many "Chosen Ones" all doing exactly the same stuff.

All this teaches players that the optimum number of other players in the same zone as you is zero. If you had the choice to play through that zone with other players or alone, you'd chose alone for most of the content and only do group content with others. At some point in the future we might actually see a MMORPG which offers the option to play through single-player instances as a feature. There certainly would be interest in that. But then the whole business model of MMORPGs collapses: Why should you be required to pay more money to play multiplayer TESO than to play single-player Skyrim, if most of the time when playing TESO you wished you were alone in the zone? Same for Wildstar, although it doesn't have that obvious single-player game to compare it to.

Fortunately there are also some bright spots. For example in Wildstar, if you need to kill a boss mob for a quest, you don't need to kill that boss mob alone, or be the first one to touch it. If you come across that boss mob already in a fight with other players, you just need to get a single hit in, and you still get full credit for your quest. And then Wildstar, as many previous games, has public events, which are hard or impossible to solo, and thus make you quite happy if there are other players around when you want to do them. So designing a MMORPG in which other players are actually an advantage is possible. I just think that developers need to carefully design all the features in the game to check how they are influenced by there being multiple players around. Telling somebody that he failed because somebody else tried the same challenge is a bad idea. Creating situations where players are automatically helpful to each other would be a much better plan.