If you had to choose between marrying a widow/widower or a divorcé/divorceé, a lot of people would prefer the former. Knowing that they have no option ever to go back to their ex can be reassuring, even if it’s for the most tragic reason. It also shows that a potential partner can commit to marriage but has no history of choosing a partner that is wrong for them.
One might think that a divorced person brings a lot of emotional baggage from their previous relationship, but widowers do as well. They might spend years not dating or even considering marriage because they are still in love with someone who is not in the earthly realm. It’s difficult to compare to an idealized image of the deceased because they aren’t here, can’t serve as a real voice of reason, nor can they share their posthumous approval of any relationship.