I'm not saying every engineer has ambitions to be in management, but your quote is just as likely someone who has become fed up with sloppy management and deliberate gatekeeping.

In the days of the rampant layoff culture, where your competence, experience, or output quality no longer matters because someone sorted an Excel spreadsheet in a particular way and had you at the bottom 10% — it should be a miracle when companies are getting this much.

No more extra miles, not a single one.

This is the result of advice being rejected too many times (and later turning out to have been correct).

Probably someone who burned out and found the work not enjoyable. I wouldn't blame him as long as he delivers.