I used to get very cross at badly-written surveys until I got the job of editing/rewriting a survey for a client. I realised how chuffing hard it is to get it right; although I made it a lot clearer and cut the damn thing down from 6 pages to 2, it still wasn't much cop.

I think creating a good survey is an art, and it requires training, but it's mostly done by people who don't realise this.