TCL is dead)))
qa.debian.org
qa.debian.org
I - and I'll add that I've published papers on using Tcl for molecular graphics, in software which still has 10K+ users - don't have any of that understanding. I know Tcl is still active, if a minority language, and is a good fit for some niches. (One of which is regression testing, with the SQLite test suite being perhaps the most famous.)
Mind you, I don't know how many of those people write scripts. Plus, VMD also supports Python, though that was added years after Tcl.
Personally, I think Tcl is better for the types of scripting that the physical scientists (biologist, chemists, etc.) - most of my user base - want to do. However, as something they developed became more generally useful, I found I couldn't easily tweak it to be part of the larger system. OTOH, while Python is more complex than Tcl, I rarely feel the need to rewrite user code in Python into C++ code, so there's a more smooth transition between non-programmer code to experienced programmer code. That is one of the reasons I switched to Python.
On the flip side, IPython and others have developed script-like meta-languages which makes it easier to do some of the things that Tcl excels at.
Where Tcl to die, SQLite would die with it. Fortunately, both outcomes seem unlikely.
Some of us are old enough to remember the frequent prognostications that "unix is dead" and was being replaced by more modern OSes like VMS or OS/2. How'd that work out?