In retrospect I guess I'm a bit disturbed that I even think about these things in terms of fame/popularity, when it should be solely about tool capabilities and power for its users. :) Shame on me, back to reading FSF doctrine.
That being said, my first impression from the article was quite the opposite of yours. I thought it was great news for CoenraadS. He developed something so useful, that it was integrated into the core. That's impressive! The plugin is obsolete now, but in this case it looks like "mission accomplished".
Of course this move would look different in other app/extension ecosystems where extensions are monetized and/or not open source.