The issue with Dave Ramsey is that he's good for people who are not good with money, essentially people who are "addicted" to debt. The best way for an addict to get better is to quit cold turkey. This means he can't give an inch on anything related to debt.
This leads to him making ludicrous statements when a situation should requires nuance. If I could borrow $20M at 2.7% I would absolutely do it. I could get 5-5.5% risk free which even after taxes would leave you coming out ahead by about 2%.
He likes to mention that people see the higher returns but ignore how risk factors into the equation and usually/often he is correct. But, we happen to be in a time where it is unequivocally a bad idea to pay off loans that were taken out at 2.7%. However, because of his audience he can't admit that now is a strange time and the typical rules may not apply, so he invokes a לא פלוג and sounds a wacky.