To repeat, the poll didn't mention seat saving. It asked about annoyances flying Southwest, and nearly half of respondents said that open seating was their biggest.
If it were a transparent hit - more than an annoyance - testimonials and focus-tested ads would almost certainly follow.
I'm largely unaffected by seat savers, sitting as I do in the rear of the plane. But the injured and peeved in the debate are dismissed at actual peril.