I think that's probably two questions.In your opinion, is Quinetic (and the likes) the future of rewiring / adding additional switches?
Such devices certainly can offer a very convenient, and potentially minimally (or non-) disruptive, way of adding switches to an existing installation.
On the other hand, if one is wiring a house 'from scratch', either in a new-build or a 'complete re-wire', then such devices represent a very expensive way of switching. I also suspect/presume that, being electronic devices, they are probably more likely to 'go wrong' than are mechanical switches - with the risk of encountering such a problem presumably increasing if one has 'a house full of them'.
Kind Regards, John