Look at it this way: saying "you made a logical fallacy" by itself doesn't hurt their argument, and it doesn't strengthen yours. All you did is change the topic of the conversation so that now you're having a meta-argument about how arguments should be made -- a topic far more robust and intimidating than even the mightiest dick. Also, there's a big difference in saying, "There's a flaw in your argument, and it's relevant for this reason," and, "You are making a stupid error, and here are some Latin words to make you feel stupider." The only reason people ever use Latin words in normal conversation is to feel superior to other people. Just ask Val Kilmer in Tombstone ...
Buena Vista Pictures
... or me in 2010 when I named my cat Res Ipsa Loquitur (The Thing Speaks for Itself) because she wouldn't shut up.
I took this
We just call her "Skullface" now. I don't know why.
If you'll allow me to put this in D&D terms: a knowledge of logical fallacies is like a ring that gives you +3 to Strength. It'll improve your defense and offense in certain contexts, but if you're trying to use that ring as a weapon, you're really bad at RPGs and the game master is going to get irritated with you, because how would you even make a roll for that?