[Linny]

Trippi ran for Dogwood, not the Robshams. If a colt is hard to manage (Balto Star) or runty (like Kelso) or downright vicious (Forego) or a ridgeling who has some discomfort (Funny Cide) they will never attain their peak on the track anyhow so the owners buck it up and geld. Based on the percentage of horses that end up being truly valuable (or more realistically, financially viable) as a stallion, it's usually a safe bet. Everyone like to play "what if?" games when a gelding becomes a superstar.
Look at it this way: If a well bred colt can't get through the NW1 level how viable is he really as a stud prospect? Geld him, win a few stakes and everyone second guesses you. What they don't realize is that with his b@lls, he was never going to BE a stakes horse.
Everyone reads about the monster stud deals for horses like Street Sense or Big Brown but most decent graded horses get sold for a few hundred thousand which you could easily make with your newly minted gelding.