This is definitely a good idea, but way harder to implement that it looks on the surface.
I already spent about 40 hours tuning the game to what it is now and it still sucks. Tuning a dynamic difficulty system would take even more time, mostly testing.
And then of course there's the question of what happens with the highscores. If one player is presented with a simpler game than the next, scores are not comparable at all. So a ranking to "prove you're typing hacker" would be difficult as well.
I already spent about 40 hours tuning the game to what it is now and it still sucks. Tuning a dynamic difficulty system would take even more time, mostly testing.
And then of course there's the question of what happens with the highscores. If one player is presented with a simpler game than the next, scores are not comparable at all. So a ranking to "prove you're typing hacker" would be difficult as well.