Punishments for dangerous tackles should be harder.
However, what Suarez did represents childish cowardice and a cynical, brutal attempt to cheat the game. It's a vile, repugnant thing to do anywhere in society and absolutely does not belong on the football field. There is no frame of comparison with any other footballing incident and no set standard of punishment for something that you don't normally see outside of 3-5 year old range class rooms and nursery/kindergartens.
It's also his third strike of doing it. And for the third time, he appears to show absolutely no understanding of the seriousness of the incident or any culpability for it. He will, going by his track record, keep on doing it.
Given the lack of precedent for this (other than Suarez himself) I don't believe any punishment would be too severe. Personally, I would give him a lifetime ban from International football and ban him from all forms of the game for one year.