There is nothing crueler you can say to a musician. Saying “you have to make your own breaks” is the equivalent of telling someone they have to be struck by lightning more often.
Dumb luck is just dumb luck. Everybody gets a few “breaks” in their lives, and it’s up to us if we take them or not. Sometimes it’s the right move, sometimes when the break comes we learn we didn’t really want what we thought we wanted.
When people give this advice they usually are talking about something completely different than random chance: they’re saying do good work, be ready, keep your head up, make the right connections, be patient, and don’t be afraid.
Breaks will come. Our job is to be ready.