The real reason MRSA is dangerous is not because it is a flesh-eating bacteria of epic proportions (it ain't), but rather because it is a body-foreign bacteria that doesn't get killed off by antibiotics. Normally these body-foreign bacteria ain't a problem, but if you use antibiotics to kill most other forms of bacteria you end up with a great opportunity for MRSA to suddenly spread like crazy. It begins multiplying like nobodies business and before you know it is causing infections (especially in open wounds). For a healthy person between 15 and 65 this ain't no thing, not much worse than any other infection you are likely to be subjected too. But for an old person who has already suffered an infection and is weakened from it? It is likely to kill them. And since old people are the main recipients of in-patient care MRSA can turn a serious bu non-lethal cause of admission (such as pneumonia) into a string of nosocomial infections that eventually kills the patient.
That's why MRSA, VRE and similar multi-resistant bacteria are a problem: not because they are unusually dangerous or lethal, but because they compound health problems in a population that is already weakened and potentially unable to deal with follow-up infections.
