[sokoloff]

They go to work for companies with the opposite philosophy. Some companies do no or very limited entry-level hiring, because they choose to hire programmers who made their mistakes on someone else's dime.

Yes, some also go into technical management or project management roles, but in my base of anecdata, that was either out of a genuine preference or because they realized they weren't all that good at coding. And of course, some leave the field, but this is by no means an industry where only 1 in 3 entrants has a spot 10 years later if they want one. If you're even halfway decent as a coder, you'll have a chair and the music will keep playing for you as long as you reasonably elect.