It's just a quote from a movie to encourage people to consider an alternative hypothesis. Movies are made by people who did exist, actually.

Yes, it was written by a Hollywood screenwriter who has led a life of no particular note. This is not helping your credibility.

Does it have less significance because it wasn't said at some ""feel-good applause light expressing conventional sentimental "" by an academic or something?

Absolutely. As terrible as academics may be, they at least occasionally are in touch with data.

I wasn't engaging in argument at all, anyway

So we're done here. Thanks for nothing.

I wasn't engaging in argument at all, anyway,

Clearly you were trying to convince someone of something. That sounds like an argument to me (if not necessarily a logical one).