If a legendary creature doesnt meaningfully interact with some aspect of Hare Apparent, then it will fail as a commander of a Hare Apparent deck
It also offers double the amount of storage space
Building decks around abilities that operate on classifications is advanced play for most, but if you carefully use the fact that a deck can feature a card up to four times, you could be onto something special Abilities and Effects : While some cards will simply feature a blurb and image, most of them will have some sort of ability or effect on them
For kitchen table Magic, thats usually fine, especially when you want to test new decks or protect premium, valuable cards by keeping them in a binder
In my eyes, this explosion in popularity within the community came from the release of Shards of Alara and the heavy influx of shard colored legends, many of which were also well suited for themed decks and underexplored archetypes