It seems just to be a very common misspelling : https://hn.algolia.com/?q=Etherium
Re:Report on Stablecoins [pdf]
by CryptoPunk on Tuesday November 02, 2021 @10:49AM
(#29082097)
He's had numerous discussions on the subject, and has been corrected before, including by yours truly. I think it's intentional.
https://news.ycombinator.com/item?id=9988438