> He was widely mocked and his theory totally rejected by - and it really isn't hyperbole to say this - every single geologist.
It is hyperbole. It is accurate to say the geological establishment was solidly against Wegener, but it was far from the case that all geologists were against Wegener; he had quite a few supporters (and even more in adjacent scientific communities such as meteorology and climatology). In fact it was a contemporary geologist supporter of the day (the oft-underappreciated Arthur Holmes) that eventually would supply the missing piece of the puzzle, namely the mechanism by which continents would drift.
In general I've never really liked the simplified story of continental drift that gets passed around because it ignores the really big stumbling block that Wegener was never able to get around which is that while he was very diligent about noticing similarities between continents he kept proposing wildly impractical mechanisms (e.g. tidal forces) that had implausible empirical predictions (Wegener's estimate of continental drift speed was eventually found to be off by several orders of magnitude). It implicitly peddles the story that Wegener's theory was essentially in complete agreement with empirical observations, but was just blindly rejected by the scientific establishment, which is not true in this case. (There are other more plausible cases where this has happened, but they are usually a tad more subtle.)
That is while Wegener's observations were first rate, his theory was deeply flawed, and not just in the way that "all theories are wrong" flawed; it had deep flaws that directly impacted its ability to make useful empirical predictions in the realm it claimed to be applicable. He proposed continental drift but never discovered plate tectonics.
Regardless, even though Wegener had an incomplete theory, his preponderance of other evidence is what kept his theory alive and eventually led to the acceptance of continental drift with the rise of plate tectonics in the 50s and 60s.