It's simply intellectually lazy to assume that that must apply universally. It's usually useful to think through how that happened and what that might imply about when the political will doesn't exist to push back against loopholes.

In the case of Uber, the class of people that benefited economically were the kind that wield a fair amount of money and political influence. This means that 1) Uber had enough revenue (and promise of future revenue) that they had the resources to fight legal battles and 2) a reasonably politically influential class of people was likely to be on their side in any potential regulatory battle. As an aside, the perceived minimum reasonable amount of regulation required for housing is a good deal higher than that of transport. This makes forward movement without the co-operation of the regulatory regime much more difficult, since working outside of the regulatory framework exposes you to real problems involving sanitation, fire safety, infrastructure, etc[1].

The homeless unfortunately _don't_ wield these kind of resources or political influence, so efforts to route around housing regulation in a way that benefits the homeless has no economic incentive backing it (and much of the time and money currently dedicated to fighting homelessness generally doesn't think of housing regulation as a problem). This isn't even entirely hypothetical; the article I linked in this comment is about a guy in LA building mini-houses for the homeless that the city keeps tearing down. I'm not even saying that they're necessarily wrong to do so, just that "derp other companies in unrelated contexts weren't stopped by regulation" doesn't even close to approach a sensible response to "regulation might impede improvement of the housing problem".

[1] http://www.latimes.com/local/lanow/la-me-ln-tiny-houses-seiz...