Um, how to put it... it leads to stunning intolerance for other kinds of "dogma", including wholesome, psychologically healthy ideology or religion. Religious fanatics might hate infidels, but at least they can understand & admit vital human feelings like faith; intolerance for "blindness" or "delusion", the insistence that there's one calculable right way to run things is culturally destructive, throwing the baby out with the bathwater in literally all cases - even iif it might spare individuals, it enroaches upon the complex, often beautiful patterns of their culture.

I hope you wouldn't deny that the "rationality" of RAND, RAF Marshal Harris, Kissinger or their Soviet/Chinese counterparts - the "rationality" of Dr. Strangelove - has been like a grey, soulless plague upon civilization. They all would've said that it produced slightly less misery than the alternatives they've considered, but I maintain that the indirect damage to humanity has been off the scale, and needn't have happened if our cleverness hadn't outstripped our sanity.

Go read Orwell's or someone else's notes about how we lost a gentler, less callous way of thought in the early 20th century, one that was so entwined with Christianity as to rot away and leave a gaping hole with the advance of aggressive materialism.