"* everyone should learn to just bind the `[' key to insert-delimited-parenthesis anyhow."
Not those of us who use logic languages embedded into Lisp. []'s are used to denote rules as ()'s are used to denote expressions.
But I concur that the lispworks behavior is surprising, confusing, and should not be taken as a general model of how most of us want to interact with the REPL. On the other hand, most of us would never have attempted to enter more than one variable into the REPL at one time because it breaks our mental model of READ.