unconditional rationalism seem to lead to a meaningless life (i.e. the shitty kind of nihilism)
unconditionally doing something because "rationality" demands it strikes me as mental gymnastics to let some symbolic-computable method dictate what we do... to follow this unconditionally is just as dumb as acting only on one's emotions
we have (are able to do) both; so let's use both.
It's best if we replace "rational" for "what I think makes sense" or "what I think is the best course of action", etc...
Which is, of course, self-evidently what one should do.
"Acting rational" is optimizing one's utility function to the best of their abilities and knowledge. It says nothing about the utility function itself, and using unconscious/emotional/instinctive thinking leads to better results for their appropriate places (including figuring out the utility function/what you care about)
You don't do mathematics to catch a ball thrown at you.