As a user example, when I load the HN front-page on an iOS device in portrait mode, I'm lazy and switch to rotate to landscape mode to see more without trimming edges and scrolling around. On most sites, I expect to be able to double-tap on a paragraph column to toggle maximize-fit-to-display-width mode and return regular all-content-on-display-width mode.
If some site prevents this, I will not buy their products or use their services, because it's a signal they don't care about usability and will inevitably waste people's time. That's a form of laziness and failure that should not be rewarded. There are usually competitors that want you to switch to their brand (except with govts). Those annoying jQuery Mobile one-sized-fits-all sites deployed by pharmacies, banks, govts and so on.
On a side note, some of the best experiences I've personally had browsing on my phone have been through VNC, if I have a good network connection. I realize that a lot of the processing gets offloaded from the phone this way, but I would really just like a more desktop-like experience on my phone. I have always been annoyed by apps that are basically just websites...The browser is often the only app I need. And mobile websites just frustrate me because they often take away features of the desktop version or make me have to use it in a completely different way and make it obnoxiously difficult to switch back (some random link at the bottom, or having to go settings -> request desktop version -> retype the url because it was changed to a mobile one -> reload the page). Browsers have had ways to change the "User Agent", but more and more this feature is either removed or doesn't even work.
I still think that the industry trend has been towards zooming, rather than in-place size adjustment.