Comment by andrewflnr

"Discovering new planets" only has the cachet it does because there are so few of them, and they are individually so significant. It would quickly lose that significance if there were hundreds of them. To be precise, it would acquire exactly the significance it actually deserves, but having diluted the meaning of "planet" as applied to the big eight in the process. We would soon want another name for the originals to compensate.

We can still be reasonably excited about discovering new things in the solar system without pretending they're in the same category as Earth and Neptune.