When I ask people to look at a website like Ryanair their instinctive reaction is often to say that it is ugly. If you ask most people to look at the most successful websites, they would also probably tell you that they look ugly.
The fact is we don’t spend our time looking at websites. We spend our time reading and using them. There are three things a great web design must be: useful, useful and useful.
He's right; usability trumps attractiveness every time. But I think that he makes an unsupported leap in finding a relationship between ugliness (or, more precisely, lack of design that most people would call "attractive") and usability.
Yes, there are plenty of sites where owners have clearly spent a lot of time thinking about look but neglected usability.
But it's hard to argue that these things are natually exclusive. There's no reason a site can't be beautiful and useful (as some commenters point out).
Still, kudos to Gerry for pointing out where the priorities needs to be.