How can Normal-types learn so many different types of moves?

Question

Is it because their STAB is not super effective on anything?

Comments

And normal basically mean versatility- I believe normal types have the largest movepool.

Answer 1

You just answered it.
Game Freak didnt want the Normal type to be under powered so they made Normal type Pokemon able to learn alot of different types of moves.
But you asked how, not why and I'm affraid only an irl Pokemon professor can answer that

Comments

i meant why