I had the same reaction. It's a one time password, so it does not need to be as secure as a permanent one, but it still feels silly to have a long password that you can just type the first few characters and have it auto complete each word, versus just having a shorter password to begin with.

That said I can see how autocompleting from the first three letters of each word for "beaver-grass-hypocondriac-shelf" might be easier for a human than typing "beagrahypshe"