In game design everything is about teaching. Everything can make perfect sense in your head but the real work is about making it about just as clear in about anybody else's mind. Learning is fun!
The designer is usually the best at determining what needs to be taught. Then he sets his learning curve in motion and ask production for necessary assets and HUD element, voice overs, upgrade system, mechanic distribution, etc... validate everything, keep testing with people who never played the game to see what information is getting across, and which one is just falling flat in pain on the pavement.
But the best is when you have a playtest lab at your disposal. The designer can sit with ergonomics and playtest experts to really design an experience where learning is completely blending with gameplay and the player is learning without realizing it or reading a single line of text. Then you're really having a blast.
I agree about texts as explanation from a personal point of view as a gamer. I sometimes wanted to start with a game and didn't read all text it was giving me in the tutorial.
But abandoning text is not necessary, as long as it is not too "meaty" (I like to use this expression - I hope I used this right. Not native English myself, so excuse me if my use of language gives anyone goosebumps here
I guess (and I don't have much experience with game making/thinking so far) it's all about a balance between methods of teaching (as you said: voice overs, GUI-help, texts) and play testing.