Yes, sometimes it’s nonsense, and sometimes it’s the right thing to do, because merges are done by users. Some of whom are wise, some of whom are idjits, and some of whom are not idjits but don’t grok the Quora criteria for question distinctiveness. Someone has to arbitrate as to whether the merge is right or not, and whoever arbitrates, someone will be displeased.
The present dispensation, we are told, is that there is human internal Quora review of all merges. That to me is as good as can be reasonably expected.