R429 - I started feeling a distaste for the "No problem" response long ago on my own, and found it interesting that lots of people share my feelings about it. I've even read articles about it.
It seems to be generational. In the past, the "Thank you/You're welcome" exchange has always been a standard conversational transaction, like "Hello/hello" or "How are you?/Fine." It's kind of like a hand-shake. In general, the response is simply an acknowledgement that the message has been received. "You're welcome" just is a way of saying "I acknowledge your thanks."
No problem adds in a measure of the respondent implying that they had somehow gone above and beyond.
Older and younger people seem to have different points-of-view about that aspect.
Let's say an older customer buys something at the store. The cashier rings it up, puts the item in a bag, and hands the bag to the customer. The customer says "Thank you."
The cashier, if older, is likely to say "You're welcome." No one has a problem with that.
But a younger cashier might look at it this way: the "thank you" implies that you just did something on their behalf, but it's simply part of the job, so a thanks is really not necessary, so you say "no problem." The older customer, expecting a simple "you're welcome" might be put aback, because they didn't think the cashier ringing up their purchase and putting the item in the band would be any kind of problem.
Essentially, the customer is saying "I end my part of this transaction in the proper polite way" and the cashier is saying "I end this part of the transaction in the proper polite way."
(And, my characterizing them as older or younger is simply a device to try to distinguish the two schools of thought.)
A long time ago, I picked up a habit from a friend who was raised in the country. When people would say "thank you" to him, he'd say "you bet." I liked that, and it became my go-to response.
But if it's really a case where I went out of my way to do something for them, and they're thanking me profusely, I might end up with "no problem at all."