Rational actually seems to have several meanings. The two most common ones being "reasoned" (thought through logically), which seems to be the meaning you are t

Rational actually seems to have several meanings. The two most common ones being "reasoned" (thought through logically), which seems to be the meaning you are thinking of and "correct" (making a good decision given the information available). Many bad arguments are made due to conflating these meanings. So much so that I inclined to agree with the grandparent that talking about things being "rational" or not isn't very helpful.