Board Thread:Questions and Answers/@comment-24351824-20140123041633/@comment-24145588-20140123155047

I can think of three reasons -- two sort of touched on by Belthazar.

Reason 1: You can breed the two-element Ethereals. Currently, there are only five of them. The Boo-Doo, Whisp, Nebulob, Arackulele, and the Sox which was just added in the past week or so. There should be a sixth two-element coming along, and then maybe they'll expand out to three-element Ethereals. Since at most one Ethereal type is allowed on each of the Natural islands, you can't breed them there.

Reason 2: Shards. Shards generally aren't as useful as coins, because there's no baking on the Ethereal Island, as you said. But, since you can't bake with them, it's easy to let shards pile up to large quantities, and buy the uber-expensive decorations. Buying and placing the Floofy Nest, Ambered Thing, and Tub Fountain will cost you a fair amount of shards, but will earn you enormous rewards in XP and coins. I wouldn't spend 50M coins on the Tub Fountain to get rewarded with 20M (and 6.25M XP), but I did happily spend 100k shards for the same reward.

Reason 3: Simple aesthetics. Most people will probably disagree with this, but I don't want Ethereals on my Natural islands. I don't think they look (or sound) right there, they take up too many beds, and at this point the coins they earn on Natural islands isn't really a consideration. The Jeeode looks okay on the Water Island (although being Crystalline, it should obviously come from the Earth Island), but the Ghazt, Grumpyre, and Reebro look completely out of place on their origin islands.

When I got my three (so far, no Grumpyre) Ethereals started on their Natural islands, that gave me 72 hours to stockpile food, to get to the required 1.3M. When they hatched, I moved a few natural monsters into a Hotel, fed the Ethereal up to 15, and teleported it to where it belonged. Of course, I took pictures to prove it happened, but I never had an Ethereal on a Natural island for more than five minutes or so.