So because he came up with some excuse about "not understanding" (I think you're being very naive if you believe that, given how long he's played in Europe) his punishment should be reduced? No way.
Ultimately Liverpool FC are going to suffer and it was (I agree with you) their responsibility to ensure he is culturally understanding enough not to be racist. So the ban is fair, surely you agree with that at least?
It doesn't mean that Suarez is necessarily "a racist" but hopefully he'll now understand what is acceptable in more culturally advanced areas of the world.
I find the ban excessive given the circumstances but would accept that the FA need to make an example of someone. I am simply saying it would be better for all parties in the interests of racial harmony if the FA could set out some guidelines for clubs to follow, and the clubs used them as a basis to educate the players they sign from other cultures. Obviously some of onus will always fall on the individual, but I can see that at the moment we have a flawed system that does not consider all differences around the world on the issue of racism.