Psychologically, it represents an inherent shift of perspective. To say "you're welcome" to me when I say "thank you" is for you to focus on how I am, rather than whether or not I'm causing a problem for you. This shift may seem subtle, but it's not. Instead of my being "welcome" to whatever caused me to say "thank you," I'm no longer welcome if your being kind creates any kind of discomfort or issue for you.
The real problem with "no problem" is that the underlying sense of graciousness that has always been implied with "your welcome" is lost. Graciousness means politeness, courtesy, charm and generosity of good spirit. None of these are connoted in a "no problem" reply.
I don't think those who mindlessly say "no problem" even consider that some hear this as a mildly rude way to respond to a "thank you." They don't hear the loss of graciousness because they didn't grow up feeling it with "you're welcome."
The upshot is this: Knowingly or not, a "no problem" reply connotes a willingness to be kind or helpful as long as one isn't being put out. But feeling truly welcome is very different than hearing that you're not creating a problem.
The writer is a clinical psychologist who practices in Newport Beach.
No to plastic bag bans
Purchasers of produce and food products would not have a ready resource to dispose of food waste in a sealed fashion, which would proliferate insect, bird and rodent growth. The disabled would be unable to carry purchases of fluids, cans or other heavy items without risk of breakage. Purchases of food, beverages and other items by tourists would be impacted and cause loss of tourist dollars.
If a ban for purposes of protecting wildlife is necessary, then limit the ban geographically to an area near the beach, not in the supermarkets and shopping areas. Collecting money for paper bags is a harmful intrusion into a depressed economy that discourages consumers. If you make shopping difficult, the customers will go elsewhere every time.