Perlis, as usual, summed it up well in one of his aphorisms:
The string is a stark data structure, and everywhere it
occurs there is much hiding of information.
This is what is wrong with both Unix and tcl. Their power is also a great weakness: they are designed around a “least common denominator” representation, strings. What it buys you is that everything interoperates. The above aphorism explains what it costs you.”