Some of the responses here say a lot more about the people making them than they do about México...
I'm baffled by the complete logical fallacy that because there is a high level of another type of crime, they should ignore customs. I assume we would apply the same to the USA, with all those murders and the gun death rate, why on earth are they putting so many resources into ruining people a day at the airport?
As a brit living in México I can assure you there are huge swathes of the country that are far safer than many parts of the US. In fact safer than London. I walk around at night in Mexico City without problem. Obviously I know where not to go like any big city.
Some things are better here than at home, some things not. In terms of the general charisma and warmth of the people, they win every time. I having been here during the response to the earthquake last year, the ignorance of some of you is embarrassing. Educate yourselves, the world is a great place if you open your minds and don't walk round looking for ways to feel superior.