What I like most about TCL is that a TCL REPL feels a lot more like a normal command prompt than Lua or Python or whatever. If I’m going to write a complex program, TCL wouldn’t be my first choice, but if a program I’m using has a command prompt (think autocad or the debug console a lot of games have). Plenty easy for one-off commands, but with a simple and powerful programming language there if you ever need it.
Put differently: The command line ergonomics of POSIX shell, with the scripting ergonomics of Lisp
Yeah, that may be why it became popular in CAE/EDA tools, one of the the few places it remains used these days. IMO Tcl works well for that use case, but it often catches shit from people who've had to use it. I think it's either because they misunderstand the language (as in the article, but also not that people who use CAE or EDA tools may have very little programming background) or that the vendor APIs provided to interact with the tool are very poorly designed (which I have definitely experienced).
Put differently: The command line ergonomics of POSIX shell, with the scripting ergonomics of Lisp