opaque to casual examination means that you simply cannot read the code. You would think that a statically compiled binary blob wouldn't be handled as if it was a perl script, but it is.
It's funny how everything that bell labs alums have touched has influenced computing in a way that isn't publicly acked and how the network and namespace ideas in plan9 and inferno have become foundational to cloud native infra. Pikes assertions in a couple cases are just wrong or exemplify naivete however. He is surprised by how a language designed to be opaque to casual examination, statically compiled and used in a majority of high profile cloud native applications (where the install is often download and run a go binary as part of an un-examined curl | sh pipeline) is happily used for malware? Also interesting how designers of languages who are formerly avid critics of PL become reticent and opposed to negativity as authors. Finally he touts the 'hard' problem of concurrency that GO offers an unanticipated solution for as if OpenMP hasn't been around as a functional approach since 98 for concurrent programming in the HPC and scientific domains.