Your point about costly investment is good, especially if you keep in mind that to have renewable house heating, you have to have both. Heat pumps to allow efficient electricity based heating, plus wind/solar to have renewable electricity, and this has to compete with a gaspipe+central heating,or even coal ovens.

A question to which I do not know the direct answer: is a heat pump run on fossil-fuel generated electricity more efficient than direct fossil heating? I seem to remember that a heat pump's big savings came from replacing aircos in summer, not from heating in winter.