I think the 12 year old baking dish most definitely did not require a replacement. There's plenty of ways the owner could have mishandled it during 12 years. I would have offered a discount on a new one too, It think that was a fair solution. I don't know, if I had other customers in my booth, and I sensed that someone might make a scene, I might have given her a new baker too. Just to resolve it as quickly as possible. An angry scene only hurts you, no matter who is right or wrong. The only thing I would have done differently is, when handing her the new baker, say "I hope this resolves the matter. Please never buy my pottery again."
On the other hand, the mug that cracked within one year would get its day in "pottery court." Probably replaced. Although she would have to send the cracked one back first so I could see what happened to it. Did it crack when boiling water was poured in, or did somebody drop it?
I used to make an item that consisted of three parts. One of the parts was delicate and small. On three occasions, customers brought back the fragile part broken. I gave them replacements on the house. One of them started crying. Another one handed me a plate of brownies a few days later. The third one returned to my booth an hour later and bought a $250 platter. So this type of customer service can benefit you in some circumstances. I will add that I stopped making that item, due to its durability flaws.
I recently had an online customer who, although he had bought a good quantity of work, it became clear to me that he did not understand what he was buying, in ways similar to the customer who thinks a 12 year old pot should be replaced. I finally told him "this is your last order." (This is one of the reasons I closed my online store.) My point here is that sometimes it is appropriate and necessary to tell a customer their business is not welcome anymore.
I would speculate this attitude is growing because of the growth of online selling, not because of LL Bean. Online selling implies things are supposed to be convenient, and customers get served while they sit on their couches. LL Bean and REI have had their generous return policies for decades. Actually REI dramatically scaled back its return policy last year, because they finally realized customers were abusing the policy.