As do I Hareeba ... but you have to look at Betfair from both a layer/trader's point of view as well as those who are just punters, and as you say, may never consider dangling a line in the water hoping to catch a fish.
I've found Canbet to have asian lines within a cent of two of SBO quite often, they're not as bad as they used to be. OK, they will limit you to 5 or 10 max stakes on horses in a blink if you're hitting them when they are out, but with football I do use them from time to time and when you factor in occasional 25% reload offers ... and I must be fortunate as I can easily get 200-500 euro on football with them