If you control three or more snow permanents, your creature not only gets a +1/+0 boost but also indestructible before it throws down
For three mana, Louisoixs Sacrifice is a lot less exciting
The card draw she provides will be valuable, whatever strategy you're going for
In this case, the spell side provides an infinite-hand-size emblem while drawing you lots of cards, and the Sea Gate, Reborn side is an untapped mana source if needed early on
This is especially popular for powered cubes, vintage cubes, dual lands, reserve list staples, and highly optimized Commander environments where replacement costs can become extremely high
It is just a game, though, so I don't blame anyone for mixing all manner of nonsense together in this crazy format we love so much