Corollary: people aren't always as boring as they may seem - digging in a little, asking questions - I often find what people are doing outside of work (which seems to be the default "interesting or not" metric) can be rather interesting.
This is absolutely true. A lot of the most interesting people I know only appear boring because they are well aware of the societal norms and won't speak out. Once you break through that trust barrier you can find that "boring" people are actually incredibly complex and interesting.
I think you missed the point of that section, the meaning is "don't be boring, try to be interesting". But I agree with you (when assuming the other meaning).
Corollary: people aren't always as boring as they may seem - digging in a little, asking questions - I often find what people are doing outside of work (which seems to be the default "interesting or not" metric) can be rather interesting.