Please Stop Telling Me How Great Defectors Are

Of all of the arguments one can make, the one I hate most is the Defector Argument.  You know the one: a famous general suddenly says, “Oh, Bush is wrong on Iraq!” when the rest have been firmly  in Bush’s camp the whole time.  Or a climatologist breaks with the other 99.9% of scientists who agree that global warming is a real thing to claim that no, this isn’t man-made, just a mini-ice age.  Or a billionaire who’s been for low taxes the whole time suddenly reverses course and admits that higher taxes on the rich are needed.
Don’t get me wrong; I don’t mind the arguments on their own merits.  Or even if it’s about a single person, as in, “I’ve long respected Joe Schmoe despite his opposition to our cause, but  today he’s said something important.”  But the arguments are never about that.
The arguments are always about, “See?  A general/scientist/billionaire believes what we do!  Look at how much more important that makes it!”
Fuck off, jack.  You never cared about any of those generals, scientists, or billionaires until they started agreeing with what you wanted.  And now you’re trying to tell us that generals/scientists/billionaires are very knowledgeable and smart and hey you should listen, when the vast majority of them are still opposing you? If their opinion was of such great import, then why weren’t you shaken in your belief when nine-tenths of them looked at your ideas and went, “No, that’s crap.”
No.  You actually don’t care what these guys think.  What you’re doing is a sad, transparent ploy to convince other people who believe that these folks are important.  Broken down, the argument is really, “Hey, I’ve been thoroughly ignoring the reasoning power and wisdom of this group all along, telling people loudly they’re full of crap… but now that one of them has defected to my side, suddenly they’re filled with insight and beauty!  Maybe you, who are stupid enough to follow whatever herd animal walks by you, will be convinced by this!”
Seriously.  Fuck that.  If you’re just going to cherry-pick your sources, then I’m not interested.  Likewise, all of those breathless articles I see posted all the time about “I was a Republican, and then I saw the evil of their party, and now I’m a Democrat!”  Dudes, there are plenty of articles on Democrats who became Republicans, and I don’t see you citing them.
The truth is, all these folks were people who had opinions you were perfectly willing to dismiss until they agreed with you.  That doesn’t make you compelling, it just means you’ve found another preacher for your choir.