In this day and age, where some games are shipped in pieces rather than a complete package, treading the line between angering fans and giving people a reason to come back is harder than it seems.
Overwatch and Street Fighter V are two games that, on the surface, have no connection. However, both were released with the same concept in mind, which was having the game launch, and then delivering free content in the coming months. One of these games has been criticized to no end over it, while the other is praised for it. The big difference between the two, to me, is fan expectation.
When Street Fighter V released, there was a wave of anger from fans over how little content the game actually had. It had the typical multiplayer, and a training modes, but for single player content, there wasn't really much to experience. This was a departure from the norm for the series and really fighting games in general, as almost all of them had somewhat of a competent single player essence, whether it be story mode or arcade. At the game's release, Capcom said they would implement single player content later on for free, but some fans are still angered over the game releasing with a staple of the fighting genre gone.
Now, what does this all have to do with Overwatch? Overwatch is in a similar boat, with it being a multiplayer only experience, with a little training mode on the side for people who want to practice. The big difference between the two is Overwatch will never have single player content. Yet, no one is really raising a stink about it like what happened with Street Fighter V.
The reason why is simple, no one expected a single player mode in Overwatch. From the very beginning, Blizzard was adamant that Overwatch is, and always will be, a multiplayer focused game. Street Fighter on the other hand, has always been expected to have some type of single player content, heck, even a traditional arcade mode would be satisfactory. It doesn't really matter that the modes are coming eventually, the fact that it's missing something it's always had at launch makes the game feel like an incomplete package.
The reason I felt the need to write this article up is because I've seen so many people complaining that Overwatch doesn't get criticized the same way Street Fighter V does. People claim there is a bias that no one is complaining about Overwatch's lack of single player content when hell was raised a few months earlier about Street Fighter's. The comparison doesn't really work though, as we knew exactly what to expect from Overwatch before the game was released. In terms of Street Fighter V, though, many fans didn't see how lacking the single player content was until reviews started coming out for it, myself included. Now, to be fair, maybe it was discussed before launch and I didn't see it, but regardless, the expectation of the game was different that Overwatch's.
Having post-launch content is fine, especially when it's free. It keeps people coming back to your game, at the added bonus that they don't have to pay anything for it. However, if your a successful and popular franchise, and ship with a few things people expect missing, there will be anger. It would be like Call of Duty shipping without a campaign or zombies mode. Are those two modes the reason people will purchase the game? Most likely not, just like no one purchases a Street Fighter game to play by themselves. However, those modes make it feel like a complete package and telling fans, "Oh it's coming in the future." isn't really a satisfying answer.
In the end, it all comes down to expectation. If all you plan on releasing is a few characters here, a map or two there, that's perfectly acceptable. However, giving out entire modes months after release that many people feel like should have been included in the base game, your going to have some angry fans. That is the fine line a developer must tread, the option of giving your fans what they expect from your game or the option of providing content that will make them come back. In my opinion, Overwatch has succeeded (expectation wise at least, as the game just launched), where Street Fighter V faltered.