Yes, 100% agreed! Your post reflects my feelings on this.
It's important to understand that something being a "logical fallacy" just implies that you can't unilaterally justify conclusion X by using reasoning Y.
But that does not mean that reasoning Y is not valid or helpful in understanding conclusion X.
Ultimately it's important to justify your views with sound reasoning, but life is full of heuristics, so often use of heuristics to reach a conclusion can be reasonable. It just means the conclusion is not definitive from a logical point of view.
Ideally you use a combination of logically sound and heuristic based statements to support an argument.
Following your Bob example... It's important that the person making the argument uses stronger reasoning than just calling Bob an idiot. But agreed that it's a totally valid point of supporting evidence.. assuming that Bob is an idiot is a fairly agreed upon statement.
It's important to understand that something being a "logical fallacy" just implies that you can't unilaterally justify conclusion X by using reasoning Y.
But that does not mean that reasoning Y is not valid or helpful in understanding conclusion X.
Ultimately it's important to justify your views with sound reasoning, but life is full of heuristics, so often use of heuristics to reach a conclusion can be reasonable. It just means the conclusion is not definitive from a logical point of view.
Ideally you use a combination of logically sound and heuristic based statements to support an argument.
Following your Bob example... It's important that the person making the argument uses stronger reasoning than just calling Bob an idiot. But agreed that it's a totally valid point of supporting evidence.. assuming that Bob is an idiot is a fairly agreed upon statement.