This is like me finding a pair of old eye glasses and exclaiming they must have been Ben Franklins since he wore eye glasses.
No, it's like you finding a pair of old eye glasses, and exclaiming they must have been Ben Franklin's because they look like glasses he was known to wear, they date to the right time, and have the inscription "BF" on them. Could the scientists be wrong? Sure, but the best evidence suggests that these are in fact Martian rocks.
Give a bunch of random people the science, and you'll find people who had the art and ingenuity but didn't know it.
This. Along the same line, not everyone who goes to college has what it takes to graduate, and not everyone who graduates with a computer science degree has what it takes to be a coder. But you will never know unless you try.
"Card readers? We don't need no stinking card readers." -- Peter da Silva (at the National Academy of Sciencies, 1965, in a particularly vivid fantasy)