Yes, is an HM, but so is Surf. And Surf is one of the best water moves in the game. And because it's an HM, you can reuse it. Strenth is normal (Meaning it can hit almost any pokemon), 80 power (which is good), and 100% accuracy (always a good thing).
So I don't understand why people seem to hate it so much
So I don't understand why people seem to hate it so much