Most of these Pokémon have more compensating stats, though (example: Relicanth). However, this is not the case with the Corsola. With 118 Attacks and Bubblebeam serving as STAB moves, Corsola fails to deal reasonable damage.
What really brings Waylord down in terms of viability is its moves. It's really a struggle to charge Hyper Beam and Blizzard in most matches. Surf isn't a bad STAB move, but it won't do more damage than Wailord's 175 attack.
It can be really cute, but the compliments usually end there for LoveDisk. An attack stat of 81 is really laughable for using a Pokemon seriously. Luvdisk's defense also doesn't compensate for the total lack of damage output.