He's right about the general public's opinion about knitters. As a child and young adult knitting in public (on public transit, standing slow-moving lines, etc.), I was often told off for knitting at my non-grandmotherly age. Now that I have reached that age, no one says anything anymore; they still stare.
People have so many activities classed as rude...…...my late mother in law thought knitting in front of anybody/anywhere was rude. I have yet to understand that line.