I don't think Stallman despised Tcl because of its EIAS (Everything is a String) philosophy. He was wary of the Tcl relationship (at that time) with Sun Microsystems, and Stallman was a longtime Lisper anyway; I wouldn't be surprised if his opinion was that everything outside of Lisp sucked.

EIAS is a powerful concept, though, which with Tcl's conceptually simple rules allow it to be homoiconic (http://en.wikipedia.org/wiki/Homoiconic) and allow for some interesting and _pleasant_ programming.

To head off one common misconception of EIAS, Tcl does not actually internally represent its code only as strings. It byte-compiles. Pure string-only parsing was replaced with byte-compiled code in 1997.

The argument for "everything-is-text" approach in Emacs interface is that the text is easy to work with and the possibilities are wide -- in this case for human. This is precisely the same argument for the choice of Lisp as a programming language the Emacs is based on -- the Lisp code is again easy to work with and gives a programmer lots of freedom, but it's easier for programs to work with S-expressions than text.

In other words, in the realm of code, the equivalent of "text" is "data structure".

I can see legitimate reasons why you'd want your text editor to display and manipulate everything as text but not want your programming language to be limited to the same.