There's a difference between being closed-minded and saying "yes, we've obviously thought about this thing that you, someone with no apparent background in our field, thought of in ten seconds". And if you're an expert in any field that gets a lot of people who are
interested, but not a lot of people who are
experts, you hear these kinds of half-baked theories all the time, often with this exact "oh you orthodox experts just can't handle my field-disrupting free-thinking!" kind of framing.
I'm a mathematician by education, and I cannot tell you how many people insist on things like 0.999... < 1 without an understanding of (a) what the left side of that expression even means, (b) what a real number is, or (c) what basic properties the real numbers have. Going "no, you're wrong, and it would take me a couple of full lectures to explain why but trust me we're pretty sure about this" is a reasonable answer to that, provided that you have indeed established that to your own satisfaction, at least.
I'm a mathematician by education, and I cannot tell you how many people insist on things like 0.999... < 1 without an understanding of (a) what the left side of that expression even means, (b) what a real number is, or (c) what basic properties the real numbers have. Going "no, you're wrong, and it would take me a couple of full lectures to explain why but trust me we're pretty sure about this" is a reasonable answer to that, provided that you have indeed established that to your own satisfaction, at least.