What is good for one person might be at the cost to someone else. The Church sees it as a good thing when a man decides to become a priest. But this is at the cost of his parents not having grandchildren, or a child available to care for them in their old age.
In older times when parents tended to have several children, there could be someone available for them as they aged. But with fewer children that is no longer the case. And if they have only one child and he becomes a priest, then there are no grandchildren. Prayers for vocations ought to include something for parents too. They might not have jumped for joy at their son becoming a priest.