Mmm, all well and good - but I have to say that I'd find single season angling about as interesting as single species fishing... i.e. not very!! Like Ian, i do relish those stark landscapes and conditions that winter throws at us... equally, I enjoy watching the daffodils come up, I relish the summer evening when a coat isn't required to stay out all night and those glorious colours when the leaves come down.
I would hate to spend three quarters of the year pining for different weather (which lets face it, may never come!)