Pashuteh Yid (quoted by notpashut): “embarrassing someone in public is far worse than never wearing a hat once in one’s entire life.”
notpashut responds: “When someone acts like a clown in public they should not be offended when people laugh at them.”
This comment completely offsets all the reasonable arguments you made earlier in the post. If someone acts foolish in public, perhaps he should expect scorn, but if you are the one laughing at him, then you are malbin pnei chaveiro b’rabim.
Your claim to be standing up for halacha is hollow when you simultaneously can be so dismissive of mitzvos bein odom l’chaveiro.