If no player takes an action to break this loop, the game ends in a draw
Beyond that, the competitive aspect could also be a concern
It is the combination with the on cast effects of the Eldrazi which make Shelldock so abusive when compared to the rest on offer
X is available across the condition spectrum, with a damaged copy starting around $50, though heavily played (HP) cards can sometimes sell for about $40
Miara, Thorn of the Glade and Nadier, Agent of the Duskenel can help enable this strategy, and Prowess of the Fair is essential for any deck that plans to sacrifice elves
Your other artifact dorks get +1/+1, so it's a nice Glorius Anthem for artifact creatures in the Command Zone