> Lack of comments

Actually I consider that a feature. If some piece of software requires some complex configuration I have to refer to some external documentation anyway. Many projects include the documentation (or parts) as comments in their configuration files (e.g. Postgres' pg_hba.conf), but I think it makes it harder to find the interesting parts.

> Readability

I think JSON is pretty readable, even for non-programmers, but this is highly subjective.

> Strictness

Good! Parsers are too lax anyway.

> Lack of programmability

Again, that's a feature: just keep it simple. Now JSON is not perfect (I would like to have a distinction between integers and floats), but it gets a lot right and it supports the most important data types and structures

  - strings
  - numbers
  - dictionaries
  - lists

that easily map to data structures found in higher level programming languages.