I know there's a text tutorial option. That's not my point. Most people will want to jump into playing the game as quickly as possible and not even consider the quick Text Tutorial. Most players won't read it, won't understand it, get crushed in melee combat, and maybe never touch the game again.
The game also shows the RPS system if you hit the Info button during a game, which I think is mapped to "1" by default. But the first day or two of release, most newbies had no idea what the mechanics were since they were never properly introduced to it.