As I've noted elsewhere in the thread, Prolog and Erlang do this too. They also use commas (and semicolons, in Erlang). OTOH, their syntaxes are pretty straightforward, so it's not hard to have an auto-indenting/highlighting editor make periods more noticeable.

I agree with you, but I think in practice it's less a problem than syntax bugs caused by ambiguities in precedence, optional "else" clauses (shift-reduce conflicts), etc.