no, Galileo.

That's rather specious logic. A surprising number of advancements have come from people who had no real credentials in their field. Occasionally, from people who had no real credentials, period. That you've never heard of someone, or that they have no previous experience that you can point to, does not necessarily mean they don't know what they're talking about. The only way to be sure they're full of it, is to systematically prove it. Otherwise, you're just making an argument from authority: "Well, I've never heard of this guy, and he hasn't been to Harvard. Clearly he's a charlatan." If you feel like someone's submission is flimsy, but you don't think there's any benefit in taking the time to prove it, say so. But don't just fall back on "Well, he has no credentials." That's just a cop-out, and you know it.

experiencing this exact phenomenon has forever changed the way i interact with my mechanic

i would seriously appreciate it if you could find a different pejorative.

comments like yours are precisely why people my own age embraced sayings like "never trust anyone over the age of 30". you're right, though; a sweeping generalization is way better than admitting that Sturgeon's Law is the norm in every generation, and you ALWAYS have to work hard to separate the wheat from the chaff.