It comes down to proportions. Let's say 10% of widgets are awesome and the remaining 90% are not, regardless of colour. Per parent's post, let's assume 1/12 of the widgets are colourful. So now (rounded roughly):

  - 9,2% -- awesome, non-colourful
  - 0,8% -- awesome, colourful
  - 82% -- meh, non-colourful
  - 8% -- meh, colourful

If you're choosing freely, you'll (hopefully) end up with the awesome top 10% (1/12 of them being colourful). However, if you're forced to make 1/3 of your widgets colourful (and there's only 1/12 of them overall), you end up with:

  - 6,7% -- awesome, non-colourful
  - 0,8% -- awesome, colourful
  - 2,5% -- meh, colourful

The previously "excluded" (or rather, not promoted) group is exactly just as good as the rest, it's just not numerous enough -- if you want 1/3 of colourful widgets naturally (instead of the expected 1/12), their averages have to compete against the rest's best, and that's where the perceived inferiority comes from.

I don't have the motives that you seem to be attributing to me, so perhaps you should re-read my comment a bit more carefully if you want to guess at what I might or might not try to convince you of.

I think that it's important to note, however, that the analogy functions without relying on any notion that the "colourful" widgets are inherently inferior. It was this point of your own that I was responding to.