In a recent beef recall, mechanical tenderizing drove the e.coli deep into the meat, where cooking might not kill it. That kind of kills the whole idea of the consumer being responsible for cooking out pathogens. Personally, I expect my food to be untainted and safe. Based on the lack of public outcry over continual recalls of tainted food, not everyone does.
ThisÂ very smart blog post talks about why grass-fed beef makes more sense from both a health and financial standpoint.