They sure wouldn't like me if that happened! I want what I'm paying for, but especially at today's fabric prices. If the person cutting the fabric cannot measure properly they don't belong behind the cutting counter.
The people behind the cutting counter at Joann's are extremely stingy in their measurements, and I'm sure they've been trained to be that way, but I get disgusted when I get home and find that I have several inches less than I paid for, even before I wash it, so I'm also picky about who cuts my fabric.
Then there's the cost of gas these days, and they know that most people won't come back and complain. Ok, so I sound cheap...but it's my money, not theirs.