You can complain about it looking "old" if you want, but it's hardly fair to complain that it's not an "actual wiki". It follows the style of the original WikiWikiWeb which predates Wikipedia by a number of years.
Best definition yet, that I've seen.
Also, virtually every type³ in Tcl can be expressed as a string, and so you can model the entire language mentally as if every value was in fact a string. If you wanted to write your own Tcl interpreter it would be pretty easy to actually implement it this way, though obviously performance would suffer quite a lot.
¹Later superseded by TIP 329 in response to the error options dictionary in Tcl 8.5.
²And FWIW I believe there's no actual spec for what error backtraces look like anyway, I think it's implementation-defined, though don't quote me on that.
³The only type I know of offhand that can't be expressed this way is an array (which is distinct from a list, that is a fundamental building block of Tcl and can absolutely be expressed as a string)
plus the result is really amenable to inclusion in another program as an extension language (tcl is too, but it has a much bigger footprint)
Really the only reason to pick Python over Tcl is that more people have picked Python over Tcl in the past.
Sometimes I'm thinking about a simple build system which is very much like Make but uses Tcl to be cross-platform and scales better to advanced uses.
Tcl could also work well in Jupyter notebooks.
Once you think about functions, classes, and modules, you better use Python.
P.S. We just setup a Slack interface to the Tcl'ers Chat, so now all you Slackers can join in to the hundreds of other Tcl'ers.