It was ridiculed because a Republican Senator popularized it, not because of evidence.
The way you know it had nothing to do with the evidence or lack thereof is that people who respond based on evidence don't usually respond with ridicule, and people who respond based on tribal affiliation usually do.
There were definitely some people saying "this is possible, but on balance unlikely given what we know today", but for the most part words like "crackpot" and "incompetent" and even "racist" were used instead. That's not what arguing from a place of facts sounds like.