I'm probably misreading this article. I've always known TCL as the quick-and-dirty user interface of choice. I guess that's not the focus here.
You SEEM to be referencing the "Tk" portion of Tcl/Tk. Tk is the desktop GUI framework that comes with most distributions of Tcl. But it has no apparent relevance to this or any other Tcl-based web framework.
This is kinda like dismissing a Java server-side web framework because Swing is ugly, or dismissing C# on the web because you don't like WPF.