In clojurescript strings are just sequences of characters where characters are expressed as \a and strings as "foo". In JS single char string is an equivalent of a character, as a side effect \a and "a" compiles to a same thing, which BTW matches behavior of clojurescript as well. Main reason for \a like character types existence is clojure(script) compatibility and nothing more.

As of :a keyword it's a different story. As a matter of fact actual (quoted) keyword ':a does not compiles to "a" string, but general references do. That is because in JS constant string literals like "load", "DOMContentLoaded" are used in cases where idiomatic Clojure(script) would have used :load :DOMContentLoaded keywords, there for it made sense to just compile those keywords to semantical analogues in JS, same as `foo-bar` lisp naming convention compiles to adequate `fooBar` naming in JS.