Does this actually happen?

[rachmaninoff_forever]

Do college professors ever enter piano competitions?  Or do superstar professionals still do that?

[chopinlover01]

I think there's an age restriction on them. I was looking at the international Chopin and it was something like "Born after ____ and born before ___".
As I'm sure you know, one of the big reasons people enter international competitions in the first place is to get recognized, and those companies want young, good looking (IE marketable) pianists who can also play phenomenally well.