It's not clear that the overhead is due to Go itself producing bigger binaries over time though. If you recompiled all the different CockroachDB versions with Go 1.8 (if that was feasible), it's quite probable that the tables you would end up with would look fairly similar to the ones you're actually showing.
If there is superlinear growth in binary sizes as the project grows – for example, if some part is O(n^2) in the number of interfaces – then that's certainly interesting. If you demonstrated that such superlinear growth is happening, and wrote an article based on that, people wouldn't be so critical.
If Go binaries are getting bigger because Go produces bigger binaries for the same source code over time, then that's also interesting. If you demonstrated that Go binaries are getting more and more bloated over time for the same source code, and wrote an article based on that, people wouldn't be critical.
But as it is, you kind of just complained that CockroachDB is getting bigger, tried to blame it partly on the Go compiler producing more bloated code over time, partly on a mystical "dark area" which you don't understand, you mentioned superlinear growth only in the comment section, and you didn't actually gather data or do experiments to prove or disprove any of the things you're claiming as a cause. That's why people are complaining.