In recent years, “No problem” has become a customary response to a “Thank you” rendered to wait staff, service providers, hosts and gift givers. By my observation, this practice of replacing “You’re welcome” with “No problem” began with the generation now in their thirties. “No problem” is now widespread enough that Judith Martin (Miss Manners) has thought it necessary to pronounce against it. I even discovered a quiz for people learning English as a second language that discusses how to employ “No problem” properly. (Wrong answers to “Thank you” are “any problem,” “a problem” and “some problem.”)
At first I found “No problem” jarring. It seemed glib, nonchalant and maybe even a little uppity. I am paying for my meal or hotel room—of course it is no problem to provide my food or deliver my bags. Am I welcome as your guest, or merely managing not to be a major inconvenience?