I went to Mexico 15 times and never had a real problem
ITs my favorite country (with India) and the nicest peoples i saw in 35 different countries ive visited, mexican peoples are very friendly, generous, funny, welcoming and easy going
That being said i dont say its all good and pink and yes theres violence (and more recently with drug war), but a lot of big countries have same kind of shit
Being Canadian, Mexico is close from here and very popular for canadian, so we receive more bad news with the media that others countries more south or in Asia/Africa/Europe etc so its screw our perceptions im pretty sure
And also for sur if you go to big ressort you will not have problem, but for myself i didnt, ive travel all around the country, i did hitch hiking, went to a lot of "dark area" , went to the capital, to many private house,,, etc..
I will recommend big time to visit Mexico... but yes be carefull... PLaya del Carmen is VERY safe... il be there in 2 weeks
Viva Mexico