Your logic is seriously flawed.
On the other hand, any aircraft without such lights would contrast sufficiently with the sky to be seen as a dark object from many miles away.
You get exactly the same effect with an approaching car at the top of a hill or rise. If you'd bother to watch you'd notice that if the car has it's lights on you didn't notice it until it came down the hill far enough to contrast with the highway. If it didn't have it's lights on you would see it at the top, long before you decided to pass that 18 wheeler chugging along in front of you.
It's not a case of "logic" ~ it's a case of contrast, and sometimes it's counterintuitive. Folks who are "blue blind" have absolutely no problem understanding what's going on. Folks with full color vision think that "brightness" is all there is involved in the issue of contrast and visibility, however they are wrong.