Reckless doesn't work like Eruption and Spout at all.

Reckless puts your opponent's HP at your level. You have 65 HP? If your opponent had more than 65 HP, he will have 65 HP after the move.

And it isn't useless at all. If you have a fast pokemon with reckless, and that you're about to faint against a full-health pokemon, it's a good chance to weaken it, and make your next pokemon faint it easily. I mean, you have a Raticate with 12 HP left, your opponent sends out Suicune at full HP. Then you use reckless, BANG, Suicune now has 12 HP. You die, but then you can send Houndoom and flamethrower it to death. Reckless is a very dangerous move for healthy pokemon and HP tanks such as Blissey, Snorlax or Kek-king.

And I surely know what grudge does, but arguably under a different name. Maybe it's malice: if you faint, the move that fainted you will have its PP nullified.