Usually it's because the wood wasn't prepared right before finishing. It may have been an excessive amount of solvent to clean the wood or just bad adhesion. There are several reasons and it can happen randomly.
Then they should price it accordingly.
In my experience, guitar warranties are often meaningless. I had a brand new Gibson LPDC that developed a finish issue. I brought it to an authorized Gibson service center to have them validate the claim. They agreed that it was a problem and sent pictures to Gibson. Gibson demanded that I ship the guitar to them and pay shipping both ways before they would agree to the claim. At the time, it was a minor problem that had the potential to turn into something like this. I said screw it and sold the guitar for the price I paid.
