Scott Karp has some of the reasons. Ryan Stewart says all we need is optimized rich internet applications. Problem is, what proportion of the Internet’s vast resources is ever going to be packaged as RIAs targeting devices? And what is the chance that your particular device will actually be able to run these RIAs where they exist? This is not only a technical problem; there is also the issue of telecom companies locking down their contract mobiles.

My take is different. Although I agree with most of Karp’s points, I reckon we have to change the devices, not the Internet. I am a relatively heavy mobile web user, and I actually have a problem with many sites that are supposedly optimized for mobiles. They tend to presume that I am using the tiniest possible screen – my mobile screen is bigger than some – and sometimes make it difficult to access the full content of the site. I end up trying to figure out how to get past the mobile-detection, pretending to be a desktop browser.

My preference then is for devices that do smart things with zooming, scaling and paging, so that the real Web is easier to use. Based on my brief hands-on test, Apple’s iPhone is fairly good at this. So is my Samsung i600, and so are the Nokia Internet Tablets that I’ve seen, to name a couple of others.

Site designers that really want to be device-friendly should never assume that the browser is capable of running Flash 9, Silverlight, or the latest Ajax libraries. After all, plain old HTML is fantastic for diverse devices – that is what it was designed for. Having this as an alternative alongside the latest Ajaxified or RIA-based UI is great for struggling mobile web users such as myself.