In reply to Cerberus1956: I bought 50m from Go Outdoors last year without this silliness. I'd not take it out on the shop because for a non specific shop I think they do a bloody good job of stocking climbing gear at decent prices, even better with their frequent sales.
Crap on bikes and bike equipment.... but then most stores are. And I mostly find the staff quite friendly and reasonably well trained.
Maybe they were taking the mickey out of this one and told him a load of bollocks as a bit of a joke.