Yes, I hear that a lot that Jan would be taken more seriously if the subject matter was more serious.
I know what you mean - people will say this. Of course, I reckon they're missing the point. The subject matter was integral to the sound. Surf music is a form of garage music (or are garage and punk just offshoots of surf?) and the lyrical content is crucial. I have been thinking of writing a piece about surf music for a while, trying to define - and defend it. The general dismissal of the genre is based on various things, mostly ignorance and the assumption that the Beach Boys were the genre. Much as I love the BBs, I really don't consider their early stuff to be "surf" music as I understand it - or at least, I reckon its very different. Part of it is vocal - I think Brian's voice was too pure, too spiritual; and Mike's voice too easy, too smooth. For me a hallmark of surf is the garagey rawness, which means singers need an edge and an element of angst to the voice. Jan had it, as did Dean; as did P.F Sloan, Bobby Fuller, Ron Wilson (of the Surfaris), and Bruce Johnston (his surf stuff was before he joined the BBs, and by then they'd moved on to other things). The few times the BBs did get that element was when Dennis sang lead (Surfer's Rule, This Car of Mine).
The general assumption that surf music is meaningless good time/fun music has cursed the genre ever since. I for one don't believe it was in any way meaningless - surf music as a genre was as philosophically complex as anything the folk, hippie and psychedelic genres would do later on. The thing is - and perhaps the problem - is the surf in general, and J&D in particular, were so deeply ironic that far too many people missed the underlying sophistication. The hippie protest songs, on the other hand, were utterly lacking in irony and took themselves with an absurd seriousness (a feature Jan parodied in the Universal Coward). I suspect that the likes of Jan enjoyed playing with his listeners. People ever since have missed the point.
Even worse, these assumptions have meant that surf has been associated with the awful "sunshine pop" of the late 60s. But the true heirs of surf are punk and garage - from The Ramones to the Barracudas (a band I consider the truest heirs of J&D - I'm also thinking of writing a piece on them!).
I know Jan once remarked that there was no such thing as surf music, just the different styles of singers/bands. But he could say this because surf music was fundamentally his sound. If others did songs about surfing before J&D, they did it with a heavy reliance on the J&D style, especially Jan's bass lines and Dean's falsettoes.
Anyways, my musings on surf probably need a lot more refining, but I still reckon I'm on to something!