I came into this comment thread thinking "why should I bother with Tcl if I know Perl" but your comment nearly sold me. When I do Perl it's because I can afford to be sloppy, and coming with a GUI sounds like a good deal!
TCL fits on microcontrollers. If I'm looking at anything other than Python or bash(for trivial logicless scripting) it's probably because I'm in a constrained environment.
That’s a hot take for one language with basically a sheet to describe it[0], and another whose “rules” are best described by “whatever this implementation does.”