It's not important because there are many quirks to this software, including a Lisp-like programming language. Learning to use it involves internalising many things that aren't common knowledge, which one has to figure out by trial and error, and the manual.
If you are seriously interested in BeeBase you'll be spending hours learning the basics of the Lisp-dialect and GUI toolkit, getting a hangup on that error message means you don't have that kind of interest. Maybe the empathy got in the way of that, I don't know.
And let's say someone makes a patch that implements a new error message that specifies which of the two rules regarding table names has been breached, then what? More complaints about the next quirk? Some other error message? Begging for a Lua-implemented query language because parens lost the syntax wars of yesteryear, describing it as miserable that it isn't already integrated?