Yes, just because they are ignoring you or laughing at you or attacking you is not reason to believe your cause is right and winnable. For example: If you dig up corpses to molest them, you would be right in your assertions that people are avoiding you, making fun of you, or trying to stop you, but that doesnt make necrophelia a just cause.

Galileo was right, though

That is why it is named that ;) People claim they are the next Galileo and they will be proven right because they are getting opposed or prosecuted or otherwise “suppressed”

It seems that you increase your odds of being right by opposing the masses

I argue against this. I would be astonished if it was true.

other name for this is "social proof" in psychology ☺️