Yes, it depends on the viewing side. Each technology comes with its pros and cons. For the different viewers a feature of a technology can be viewed both as a pro or as a con. However the HTML was the first and it will be hard for Silverlight or any other technology to beat it and overcome it, I dare say this is impossible.
For example, you said, that the HTML is ugly to read, but in fact it is pretty common with the XAML, as they are both markup languages. There are differences, but in the core, they are the same. In the end it all depends to which one you are used to.
Anyway, the topic is focused on the features that Silverlight 5 will bring to us. To be honest I am still not familiar with any of these, haven't had the time to test the beta even. So will there be something tremendously awesome in this version, something like full support for 3D? ^^