Given how strong all of those abilities are, its only natural that thisll see a lot of play, even outside of purely colourless decks
It's good to be aware of these archetypes because they sometimes come up in Limited, like the Lost in the Woods "combo" in Dark Ascension Limited, or making your own surprising imitation of a Fog deck by just drafting a pile of removal and no good win conditions
Bloomburrow was only given about two months where its being opened and getting all the attention
It supplies a ton of reach at a flexible casting cost
If you sacrifice a creature, (say it's an artifact creature, so use Osgir's ability), it will die, then be exiled (due to Hofri's trigger), this will create a 3/2 Spirit creature token (due to Quintorius' trigger) and a copy of the original creature that is also a Spirit
Myrel easily snowballs by giving you a number of soldiers equal to the amount you already have, which will be stronger on your next turn, and so on