Way over the top for me, I can only assume the ban length relate to previous conduct because the individual incident wasn't all that bad.
I think its a bit of both. Biting is still seen a bit like spitting as just being one of those things that is just low (in all sports). Didn't a rugby player get an 18 months ban for biting? It is harsh when compared to some others tho who have had some horror tackles. IMO its those other bans that were too short tho (or non existent) rather than Suarez's being too long (especially as he is a repeat offender).
We've got it all wrong in this country for me. I'd rather see someone do what Suarez did, rather what McManaman did.