yet every assumption is not a hypothesis...or at least a scientific hypothesis. Not saying you fall into this category but many people use the word incorrectly, without the ability to test the hypothesis. If it can't be tested and proven false, it's pseudoscience. But yeah, the AC's post seems to be from the mid 1920's and ignoring all progress after that.
Even Darwin himself made note of potential objections to his theory, as his original "Origin of the Species" was published before the Burgess Shale discovery, and he stated that "as of yet" the fossil record didn't back up his hypothesis. Yet we've found many (well, a few lol) pre-Cambrian fossils now...but many Creationist still will adamantly scream and yell that Darwin himself "said the theory was wrong" because 1. they don't understand the times it was published and 2) refuse to recognize anything that changes their internal world view.