I agree with that, although I am all in favour of a well-placed "muttered", "whispered", etc.
In general, though, I prefer dialogue to be as uncomplicated as possible. I feel that if a flowing dialogue is suddenly interrupted by a "said" or "joked", it's distracting. I also feel that punctuation, if well used, can be very effective in describing emotion, etc - why waste paper writing "he exclaimed", when this little guy "!" can do the job for you?