Bruce Lawson gives a great explanation for what I feel is true:
“The vital point is that you never know better than your users what content they want.”
Absolutely! I’s one web no matter which device a user got, it’s not the designers or developer’s job to decide which version of a web site that user gets. Akin to taking control over one’s browser, serving a separate site to a mobile user does not sound right. I can see removing embellishments like extra graphics, slideshows, and so on, but to remove or alter content and features because the site owner “feels” it’s not important on a smartphone (or a feature phone for that matter) is a whole different matter.
Bruce also discusses real life constraints that make a separate mobile web site a necessity and inevitable downsides of this setup like inability to reliably sniff mobile browsers, leaving mobile users with incomplete experience if they never access the web with a desktop, and in the end cites The W3C Mobile Web best practices:
“One Web means making, as far as is reasonable, the same information and services available to users irrespective of the device they are using. However, it does not mean that exactly the same information is available in exactly the same representation across all devices. The context of mobile use, device capability variations, bandwidth issues and mobile network capabilities all affect the representation. Furthermore, some services and information are more suitable for and targeted at particular user contexts.”
At best, it means richer experience for more sophisticated devices that have less bandwidth constraints, not revamping a desktop web site to suit some theory of what’s better for the mobile web.