I wouldn’t say it is ignored, more that it isn’t particularly useful. Shaky YouTube videos don’t allow for much in the way of study. Even more convincing sources, such as that video released last year of the Tic Tac UFO, were interesting, but not all that useful.

I agree. To talk about the possibility is to commit scientific suicide. Even cautiously talking about the topic immediately outs you to others as a crackpot. I think it's undeserved. Especially when we are now seeing just how many habitable world's are out there. It seems plausible that we have been visited by curious extra terrestrial civilisations. The bizare patents coming out of the US navy suggest to me that no one knows where these things are coming from, if they are real.

Indeed, if this theory is correct what we should expect to see are individual, small expedition-like visitations, which aligns roughly with the limited bits of credible ufo-related data.

One would have to assume that UFOs are piloted by aliens which since there is no proof alien life exists it's a Fool's errand.