Personally, I don't care for the comedy either. Boiling jokes down to pure ethnic or cultural stereotype is, in my opinion, lazy comedy (and why so many people do 'black comedy' or 'hispanic comedy.' It's easy) I've seen some comedians spice it up with new material, especially the likes of Eddie Izzard who makes comedy much more intelligible than Hetalia. But 'Italy' going "Pasta pasta!!!!" is neither intelligent nor creative. It's just...slapstick trite.
Honestly though its not a good history replacement I do kind of imagine hitalia characters in history class.
Like when it says america didn't get involved with world war 2 until pearl harbor i imagine america ignoring all the fighting in the background and an apple hits him because Japan threw it and he goes off and attacks Germany cause he's bigger.