In retrospect, that track does sound pretty good. It was a huge hit of course, but none of the obits mention the backlash that developed against the band almost immediately. In the late 70s, the worst thing a band could do in the eyes of US punks/new wavers was to somehow "sell out." The Knack were considered complete sell-outs: fake new wavers. No cred whatsoever.
My most vivid memory of the anti-Knack backlash is of a T-shirt I saw on a concert-goer around 1979 or 1980. The T-shirt was emblazoned with the words "NUKE THE KNACK!"
It's a stark contrast to the current situation, in which most musicians actively try to sell out -- as quickly and as thoroughly as possible. Clothing line? Check! Mondo merchandising? Check! Get your song on monumentally stupid TV soundtracks? Check!