I think that argument is balderdash, and I expect that it will be rejected by the courts pretty quickly.

The operative language of the 14th is to prohibit someone from serving in office if they "have engaged in insurrection or rebellion against the [United States Constitution]" or the United States itself (the language is a bit fuzzy). It is a very disputable point whether Trump did that. He hasn't even been charged with insurrection or rebellion. While he might have violated a number of criminal laws in his efforts to get Congress to take certain actions, it is debatable - and probably not true - whether those crimes constitute the crime of insurrection or rebellion against the United States.

A criminal conspiracy to falsify election results or get named the winner when you didn't really win the election to lead a governmental body isn't the same thing as a rebellion or insurrection against the governmental body. They're both incalculable threats against democracy, but that doesn't mean that the former is the same as the latter.