MOBAs are known to be intricate, unforgiving PC games. League of Legends is one of the most popular at the moment (#1 PC game in terms of hours played for May 2014 according to Raptr). It is free to install and play, with small purchases to unlock more content ("microtransaction"). The free-to-play business model is quite interesting, albeit polarizing, because your commitment starts when your users installs your title, not ends. This often leads to one of two outcomes: abusers of human psychology or constantly developed, great games that strive to never get boring.
Now you can see why it is polarizing (or just read our impending comments).
The business model does permit games that are deep in gameplay mechanics, however, if it keeps a core user base playing (and buying additional content) forever. Unfortunately, this also makes it difficult for new players to join — especially when it is competitive and multiplayer.
Riot Games noted that they were uncomfortable with how many of their players lose "Battle Training", which is supposed to be a tutorial. Some even prove to have significant skill later on. They interpret this as the problem being how they educate new players. There is high complexity that is fair, and then there is just bad user experience.
"Intro Bots" is designed to be a mode which adjusts its difficulty to match the player currently, and as they progress. Hopefully it works. Obviously that is the limiting factor. It does seem to be designed reasonably. It teaches with repetition and in realistic scenarios.
Intro Bots is coming soon, after a brief stop in public beta. Ironically, the public beta realm was refered to as "PBE"… in a press release for a feature intended to be easier for new players. You know, the people who might not know the game's vocabulary. Just saying.