Why do you assume he meant it in a deprecatory (is that a word?) way? By analogy, when one says Lisp has no syntax it's not meant in a derogatory sense, on the contrary.

It is in fact a great language. For one thing, our alphabet is fully phonetic. And it's even arranged in a logical grid: http://www.omniglot.com/writing/sinhala.htm

It's also a great language to tell jokes in. We have a lot of delivery-based humor that gets completely lost if only the meaning is translated (which is often the case when the destination language is English).

Some of our original deficiencies: we didn't have punctuation or even spaces before they were introduced by European colonists (Portuguese, Dutch and British, in that order). So our ancient writings LOOKEDKINDOFLIKETHISANDWENTONFORPARAGRAPHS.

I think that's a "feature" of lots of writing systems, punctuation and spaces and lower case and other formatting is one of those things that's obvious only in retrospect.

And the grammar is probably a lot less obvious. The classroom experience teaches most of us to look for things like adfixes (prefixes and suffixes) and "parts of speech" and call that "grammar", but grammar is much more than that. In a language like English, for instance, stress, intonation, elision, contraction and "white space" all have grammatical significance (with rules for use that evolve over time, have dialectical variations, and are almost never taught directly). Squiggles on paper (usually) don't capture much of that.

Fun fact: The mix of Sinhalese - English is called Singlish here.