I can only remember two cows prolapsing (uterine - 0 vaginals) (dang I hate to type that - don't want to jinx us) - it was an assisted birth on a heifer. Kept both, never to be repeated by them or offspring.
Yes, there can be inherited problems, but some are management. It takes a MANAGER to weigh the decision.
I Luv Hfd - did they have calving difficulties? maybe they had small pelvic areas that were passed on to their offspring - maybe in your case, it was heritable. But, as said, research says vaginal prolapses are more likely hertitable than uterine.
As I said in another post - not everything is black & white. You must manage your own herd to make the best/most profit. Whether that profit is in immediate $$ or genetics or just a humane decision.