Kumbhakarna and Meghnada-Villains or Duty Bound

I was wondering about this since a long time.These two characters from the Ramayana-Kumbhakarna and Meghnada.Do they deserve to be considered as villains too?Why are there effigies burnt along with Ravan's every year.As much as I know,Kumbhakarna tried to persuade Ravan to give up and return Sita.Both Kumbhakarna and Meghnad were honour bound to fight for Ravan.Do they deserve to be villified?