Both of these illnesses share something in common other than the burritos they apparently are lurking within: they are both transmitted through the fecal-oral route. What that means, in terms a kindergartener can understand, is that poop gets into the food. This can happen with suboptimal food handling in a restaurant (which happens to be the case with Qdoba with its own version of Typhoid Mary) or at some earlier point (e.g. during harvesting).
In my view, E.coli O26 -- which elaborates shiga toxin, a cause hemolytic-uremic syndrome which can progress to kidney failure and death -- is a much more serious outbreak. Typhoid, though deadly in prior decades, is treatable with antimicrobials and because, in this case, the source is known will likely be quickly contained.
What is special about burritos and other similar foods is that they are comprised of myriad ingredients -- just imagine how many herbs, spices, and vegetables are in salsa. These ingredients can come from multiple different suppliers which magnifies the chance of contamination occurring.
The industrialization of food is an enormously beneficial development that is hugely economical and has driven food prices down. This trend allows the average person the ability to sample exotic cuisines from all over the world. The risk, which is present with all types of food, is that contamination may occur and illnesses such as these can occur highlighting the need to be vigilant once these outbreaks are identified.