Why is Typer Shark so hard

Typer Shark is hard because they are trying to challenge your typing skills as you progress onto to higher levels and a higher diffiiculty mode. If you are a slow typer, do the easy mode. If you can type good, but not so fast, put your skills to the 2nd difficulty;normal, and if its hard for you, then try easy. If you type real fast and real good, put your skills to hard and expert. If you managed to master all 4 difficulties, bring your 'A' game to the X-Treme.