Because CME was already taken. :)
My first foray into Tcl wasn't very well informed, and it seemed like just another scripting language, with lots of different kinds of brackets and slightly annoying sensitivity about line breaks. Later I rediscovered it and it clicked: ah, it's sort of like LISP with shell-like syntax!
After Java, the combination of Tcl and Tk was like a breath of fresh air, and now I have little tolerance for languages that require you to write more than you should have to. By making it so easy to develop and test incrementally, Tcl/Tk has let me do things I would never have done otherwise, even though I find I can write Tcl more easily than I can read it. I love being able to run commands within a running application when debugging or developing new features. It's a fantastic glue language, and there's so much great stuff built in, but when you need more, you can easily extend it.
I've used Tcl mostly in some robotics and acoustics projects, including TclJACK , an extension for the JACK Audio Connection Kit plus Tcl/Tk GUI for controlling it, Melonade , a debugging package, and Piaf , the beginnings of a text editor. The statusbar widgets for DeskNerd are in Tcl/Tk. Lately I've been working on a control panel and G-code player for my 3D printer. All slightly shoddy works-in-progress. :)