[captainmuon]

I don't understand why sometimes the submitted title must slavishly stick to the original title - otherwise it is considered editorializing - and why sometimes it's OK to change it.

In this case, "The most underrated feature in Python 3" was a fine title. It brought across the excitement of the post's author for this particular feature. I agree, it is a bit link-baity, but a much better version would be "Chaining exceptions is the most underrated feature in Python 3".

The current version ("An underrated feature in Python 3") is extremely nondescript, and I wouldn't have clicked it. It's almost like "A feature in Python 3".

If you object to the use of "most"... the author is obviously using hyperbole. There is no objective measure of "underratedness" of course. I wish people would not take everything so literally, and try to interpret a bit what they read instead. What the author wanted to say was probably (and this is an equally good title): "I really like that Python 3 has chained exceptions!"