As a kid, I grew up next to a lady who had bees at home. Quilting bees. Everything by hand. They believed handmade was "quilting" and machine-made was "sewing." To them, their way was the only real method. Period. It's just an opinion (I probably echoed it in my youth).
No worries. Just remember for every one of them, there are thousands who disagree. You're a quilter who quilts quilts on a machine.
And, it was very rude of that woman to make a negative statement to a stranger in public. The nerve of her.