I used to work in construction in a previous life and always said I could judge how good a tradesman is simply by their appearance. The same goes for their website. If they have pride in their work it will show; if they do just about enough to get paid it will also show.
Interesting. I'd personally rather them be great at what their job actually is and not waste time on a website. I think the best tradesmen don't need a website because their work (and their happy customers!) speaks for itself.