There is nothing saying they can't. You might be confusing it with something else. Oni's are just very honest/don't lie(with Suika kinda skirting that rule), so whatever a Satori youkai would read would pretty much be whatever they want to say anyway.
But I'll just scare 'em if I go see how they're doin'...Starting day two of celebrating a year since Yuugi-sama left!What colour is your blood!!?When the Party's OverParental AffectionWonder if the folks on the mountain are gonna catch cold or somethin'...Gotta bear with it here for their happiness…Uwah! A youkai from the Underground is attacking us!!We'll drink today as well!
