No love for ThinkTank?

I see a hell of a lot of people use Lowepro bags, These are the bags that tend to hang around camera stores like Jessops etc

Does anyone else out there use ThinkTank bags or do you think its just the price that puts people off? I use a Retrospective 30 and I think its a good, sturdy and well thought out bag. Was just looking for opinions on why you don't see them around more compared to the other brands..