Travel agent: Although most low-fare airlines have had few, if any, accidents, very few such airlines have been in existence long enough for their safety records to be reliably established. Major airlines, on the other hand, usually have longstanding records reliably indicating their degree of safety. Hence, passengers are safer on a major airline than on one of the newer low-fare airlines.
The criticism to which the reasoning in the travel agent's argument is most vulnerable is that the argument draws a general conclusion about how safe passengers are on different airlines on the basis of safety records that are each from too brief a period to adequately justify such a conclusion.