Or perhaps, he wanted to be free of the constraints of imposed man-made ideas because he felt they made no sense to his practical observations.
But that's a terrible reason to leave academia. You may not have noticed (I don't reckon you follow the peer-reviewed literature) but the most meaningful and important papers are ones that
challenge our conceptions, and provide a new way of looking at the world. Koonin's most famous work seriously challenged a lot of ideas held within the theory, and did much to drive the science forward. If Menton was truly interested in challenging the paradigm, there's no reason he shouldn't have stayed in academia. Of course, academia has slightly more stringent fact-checking than AiG, and if he had tried to publish his absurd piece on Tiktaalik in Science or Nature or Cell he would have been laughed out of the room and possibly blacklisted for how outright dishonest it was.
It's funny you should say that because all we keep hearing is that scientists who reject evolution cannot do real science. Thanks for confirming that oft-quoted fallacy.
It's a bit like saying "mechanics who don't know how to change a car oil filter can't be real mechanics." My buddy Ulli couldn't do that and he's an incredible mechanic. It's just that he doesn't work with cars, he works with large automated assembly-line machines. By a similar token, I don't expect any young earth creationist to be a good biologist. It's just not really possible, unless their work in the peer-reviewed literature is fundamentally opposed to their work in the creationist literature, like with Andrew Snelling. They could probably be perfectly good computer scientists, though, right up until someone asks them to design an evolutionary algorithm.
Every argument deserves a "level playing field." Otherwise, how can you possibly have an unbiased result?
Do you think the playing field was so "biased" 150 years ago, when Darwin first proposed his theory? Well, actually,
yes, it was. Just in the opposite direction. Darwin had to overcome not just scientific inertia, which is both real and rather important to the method (an idea supported by decades of research should not be immediately discarded at the first anomalous result!), but also significant
religious bias, from people disgusted by the idea that they could be anything but created in their current form by an omnipotent deity. What you seem to asking for is that we reset the scoreboard after 150 years and pretend none of it ever happened. But even if we did that, guess what: the evidence for evolution is as strong as it ever was.