Do you have some specific examples of irrationality? I’m curious to know what you’re encountering, and I haven’t yet found this among the non-religious meditators that I know.
I do avoid them (figuratively, not literally) because I value my critical thinking.
What I observe in meditators is a gradual loss of trust in logic, reason and science, even in those with decades of education. They fall for silly quackeries and psychic beliefs or that the meditation teacher mystically can know things and have insight beyond even experts.
If they produced some new knowledge through that, I would be all for it. But no, it just is a collapse of common sense.
This is again all very vague, so it’s difficult to understand your perspective. Silly quackeries like what?
It also doesn’t align with what I’ve experienced, or have observed in others: I’m still a staunch believer in logic, reason and science. Have never felt the need to take on psychic beliefs, etc.
I’m not saying you’re wrong about the people you’re referring to, I just don’t have a similar frame of reference.
The recent scientific interest in meditation is primarily focused on the mindfulness variety, which is more about observing your state of mind without judgement, and learning to stop getting lost in discursive thought, vs. TM's focus on mantras. (there are TM studies, but mindfulness has gotten wider attention, with good reason I think).
While the mindfulness family of practices has been well secularized, it does seem that TM brings a lot more baggage along with it.
I think this still boils down to the person practicing. While researching/evaluating meditation practices, TM was something that I decided to steer clear of, for many of the reasons you describe.