Well, one thing is that it's sort of a fault of Handlebars that there's a syntactical ambiguity between `{{foo}}` as a property lookup and `{{foo}}` as a helper invocation that can only be resolved at runtime; this is both inconvenient for developers who can't look at a template and know whether `foo` is a helper or property lookup, but it also bloats/complicates the compiled Handlebars template itself with logic to resolve this ambiguity. Considering we now have a means of avoiding this ambiguity (by way of subexpressions being surrounded by parentheses), why would we want to bring this ambiguity back into subexpressions when you can just omit the parentheses to opt into a property lookup?