True. However it's a tactic commonly used when all else has failed, and the speaker is desperate. Best to avoid it.
Any speaker may do the best he or she can to make themselves understood. How listeners receive what is said, assuming reasonable clarity on the part of the speaker, is still up to them and not the speaker.
A majority of people, it would seem, had no difficulty understanding the OP's intent with his meme; you, however, chose to focus instead on creating an issue where none had existed. You, my friend, are one of the very few in this thread who seem to be having difficulty with interpretation of what most consider to be clearly phrased English with obvious intent.
If that was the intent of your original comment, you should have said exactly what you meant. You, my dear sir, failed to communicate clearly. Which is amusing, since that is precisely what you accused the OP of.
Hmm. Funny how you comment on my not addressing your point, when you won't comment on what has been said about spirit vs letter. Care to explain your odd taciturnity?
If someone says "black people are criminals," why do you suppose they say that? They know as well as anyone else that not all black people are criminals, and not all criminals are black; very clearly, a degree of bigoted hatred is indicated in their mindset which leads them to make such an obviously false claim.
If someone says "Christians are child molesters"...only someone who hates Christianity would make such a claim. For the same reasons as above.
And as far as the statement "Jews are greedy swindlers", again: there is clearly a large degree of hatred implied.
Do you suppose, then, that the OP intended to say that every last 18-year-old male today is an emotional trainwreck? Because the OP hates all 18-year-old males? Or merely that, in general, adolescents today are overly focused on themselves and their own emotions? Which, do you guess, is more likely to have been the point of the meme?
Legalism is merely adhering excessively to law or formula (direct dictionary quote). It refers to a type of behavior and is not limited to religious topics of discussion, though it may be commonly used therein. It refers to spirit versus letter - a legalist will ignore the spirit with which something is said or done and focus only on disputing the particulars.