When talking about website development everyone considers the staples of web technologies as HTML/XHTML, CSS and Java Script. This is how websites have evolved over time and we all understand the individual uses of each technology and therefore when to substitute them for something else that would be better. For example, rather than coding something to display a set of data using a lot of the above technologies you could quickly use an XML and a transformation file with a dash of CSS to make it look nice. These technologies fit together in different ways.
Is it good? Is it bad?.. I think it is a bad idea.