Zinnia's primary ability, to get +X/+0 for each other creature you control with a base power of one is almost forgotten about with this ability, since you can make the most of your enter the battlefield effects and other strong effects to let you duplicate them
You might not have the speed to get quick kills, but you reliably get the mana you need on later turns
That is literally a badger playing a drum solo on someone's skull with their bones
Green creatures will often feature large creatures with the keyword Trample, that allow you to apply excess damage to your opponents health, even when blocked by another creature
It's the same reason people play the lottery despite knowing the odds: the dream is worth the ticket price
I often prefer these types of cards to short term draw spells in decks that always need to be keeping fuel in their hand, and while this doesn't really provide a full card in hand it doesn't make you lose life like Arena