Taking the opportunity of a man's death to call him overrated is not speaking truth to power: it's tacky and tasteless by any measure.

Don't pride yourself too much on being "honest". It is far easier to go around always telling the truth than to apply discretion.

Typically people understand being brutally honest as providing a painful to hear but helpful or contributory opinion.

When your opinion comes from nothing but arrogance, ignorance, and a 4chan style need to draw attention to yourself by being deliberately insensitive, then your opinion isn't brutally honest. It's worthless, and you should keep it to yourself.