Not to long along I was reading about formal and informal fallacies and found one that caught my attention in a unique way. The genetic fallacy which is an informal logical error where a claim is accepted or rejected based solely on its source.
For example: "That idea is stupid because it came from X political party"
So, I understood it as if I say "I need to lose weight" and another person who is clearly has more body fat composition than me by far says: "Yeah, you look fatter. You should do cardio and talk with a nutritionist." I shouldn't reply "look who's talking" because that doesn't make his argument less valid. If I want to counter that argument, I would need to find another that that focuses only on the argument and not the person who said it. That person is been a hypocrite right? but his argument is true logically because I am not in a healthy shape and diet with cardio can get me there; even if the person who said it doesn't follow his own suggestions and it's supporting my statement.
So, is logic and critical thinking supporting hypocrisy?
Where can I learn more about the topic?