But...why should some direct investment towards "housing" if they can direct them towards the day-rentals ? Its definitely in their economical self-interest. So as long as we allow these platforms (be it AirBnB, Amazon or FB) to amplify a single parameter at the detriment of everything else in the society as a whole, I am afraid all the philosophical discussions about "complex" aspects will not help.
This is a supply/demand problem. Your solution is to restrict the supply of short term rentals. Restrictions rarely work, the hypothetical situation you mention would benefit from allowing more building of long term rentals.
No, I did not suggest the solution you are implying my comment meant. What I am saying is that these PLATFORMS are not the right way to handle the supply of short-term rentals, as they incentivise the home-owners to take them off the market for long-term rentals. I would be perfectly fine with short-term rentals which were not the converted living units. We have to think differently here. But if the push comes to shove, actually restrictions would work here in favour of the long-term rentals, because being, as you said yourself, a supply-demand problem, it would raise the supply of long-term rentals and reduce the prices. Just as it was happening before AirBnB. Its just that we have to be moral enough to recognise that the basic human right of a local in a tourist location to live affordably is set higher than the luxury problem of the so-called digital natives, namely, booking a short-term rental in a city center (so they can produce yet another piece of "content"). Not to mention that a platform which does not generate profit should not even be allowed to exist.
Most of the case it is because more building is simply not possible.
And anyway as long as there is no restrictions on the day-rental, investor will choose the option in their economical self-interest. Restriction must apply to force long term rentals.