The blog post would be more helpful if it provided readers with more details, and also if it were based on more experience in Mexico than "Our Oyster's" guest blogger Alex has had. The good news is that Alex has actually been to Mexico. (Many who post about safety there have not.) Also, she successfully conveys to readers the fact that wide geographical variations exist in Mexico today regarding safety, due to the drug war.
Part of the bad news is that Alex overgeneralizes, making vague hyperbolic statements such as:
"Half of Mexico is very safe (southern part), and the other half extremely dangerous."
And, her hysterically phrased advise about the potential hazards of "choosing a taxi" is not pertinent to most Mexican towns and cities. Many other cities and towns have not experienced the extensive taxi related crime that Mexico City has suffered. Contrary to Alex's claims, even in Mexico City, most taxi customers are not assaulted and robbed.
I find the blog's photo that is captioned "safe taxi' humorous. Does Alex have psychic powers enabling her to determine from it's appearance going down a Mexico City avenue just how safe a particular taxi is?