A lot of the focus on simplicity is about ease of implementation. A compiler/interpreter for a language without syntax (Forth) is much faster/easier/simpler to write than one with syntax. Originally Forth was an OS as much as a programming language, and the strength of the concatenative paradigm for command languages can be seen in the enduring popularity of pipes in *nix shell. The syntax is not considered a problem because it will be invented as you go along and write the words that implement your application.