You may criticize anything I've ever written that you can find. As a software developer, that's my daily assumption.

The increasing adoption of code review tools like Gerrit is one of the best things that has been happening in recent years.

No piece of code I've written in the past few years on the job has gone into the stream without the approval of several people.

Frequently, it had to be revised. More than once.

No, because I'm bound by contract, cannot disclose my source, and I'm under NDA. That said, my comments are not unreasonabe or overly critical for C++11 or newer code. Quite honestly, if I desired to, there's more I could probably find issue with in even that small of a code sample.

It's not unproductive. The project was linked, and code quality is relevant.