Some games don’t have a need for a tutorial as much as HotS does (Even when they have one) because they simply are less complex. There are many games where I got really good. But for most of them I didn’t need to put as much time as I did in HotS to reach an acceptable level.
For example, Guilty gear has a training and a combo tutorial (Fighting game) While doing it won’t make me a pro, it does teach me everything I need to know to play the game beyond the basics of attacking and blocking. Most of the combos showed are combos that actually work, and that you can see pro players use. Some of them may be hard for some players, but after going through the actual tutorial, you no longer have any bad habits that your opponents could exploit, because the tutorial tells you why you should do what it shows you.
Furthermore, HotS is a team game. If you only know which buttons to press to use your abilities, and that objectives are important. You are going to drag your team down. Your knowledge, or lack of, does not only affect you. The players who make the effort to learn are still punished by the lack of knowledge of those who don’t.
So it’s very different from a one on one or free for all game.
I will also add that, in most competitive games like fighting games. Within the same genre, the basics are more or less the same. What you learn in King of Fighters for example is mostly transferable to Street fighter. It isn’t the case between HotS and other MoBAs. Even the concept of experience is different.
So player need to be taught that, for example, early game, a kill is worth less than a minion wave. So they’d stop wasting time chasing the lowest value while ignoring the highest.
It doesn’t matter that some people can skip the tutorial. If there isn’t one, no one at all can benefit from it. If you made a cure for cancer, some people would flat out refuse to use it. Does that make it not worth making one?
I have yet to play an ARAM game where most of my team doesn’t want to win. When they think someone is causing them to lose, they get just as salty as anywhere else.