I did use Dive successfully with Ludicolo before in Generation 3. We had a one legendary per team rule and so I had Kyogre. With Ludicolo, I had Dive, Toxic, Leech Seed, and Giga Drain. The strategy is pretty simple. With the rain out, I had Rain Dish activated, add in Leech Seed (and I think it also had Leftovers) and you got a monsterous healing machine. Dive allows me to stall one turn. Giga Drain allows for some emergency healing (or when like a water type is out on the field). Plus, toxic is always plain old fun with a staller.
I do admit Cut, Rock Smash, Whirlpool, and Defog are bad even in game. Cut is a decent move at the start of the game...but that's also true with Tackle and moves like that. I actually kept Tackle on my Stoutland for a while though... It was good for when I just needed to weaken something to catch it. But, I digress, Cut is a movie to me that looks like it should stay as it is as just an early game move. Rock Smash was always pretty bad both in game and competitively. If Rock Smash lowered defense maybe two stages with 100% success rate it would work like a Screech that can do damage. That would make Rock Smash better in a similar way to why Mud Slap is better than Sand Attack (as long as you use them on the types that aren't immune to it). Whirlpool is like a water typed Fire Spin, nothing in particular to see here. Defog only has a single situational use for a single situational attack; dispelling mist. I did use the other part of it a couple of times (stupid Double Teaming guys) but you won't see that in competitive play. I can think of one way to actually make it good enough for competitive play: if it actually could dispel any weather effect. Not like Rayquaza where he just ignores it, but actually getting rid of any weather in the battle.
Now for the others, Strength, Rock Climb, and Fly saw use in game. Especially in Generation 4 when I didn't have unlimited TMs, they were decent moves to be used on in-game teams (not good, but decent). Especially, Fly. I still used Fly on all my birds but that's because there aren't many good flying moves... Meanwhile, Surf and Waterfall are great competitively.
I do wish there was a way you could delete HMs though. They didn't allow that before because you could deposit it and then be left stuck, but now, especially with the item PC gone, we could always overwrite the move with the necessary HM