I get your point, but I want to quibble. I want to suggest that enlightenment in the terms you use it should eradicate the neurotic attributes that make some folk not at all very nice. Of course the core personality may not change its essential style - but there's a distinction to be made between 'niceness' as an aesthetic attribute and 'incense' as opposed to nastiness.
For example I work with people with whom I have no easy flow, but who are still people of integrity and compassion. I would not say interacting with them is pleasant (i.e. not nice), but I also know their integrity is impeccable (i.e. they are a nice person).
Its an important distinction.
On what are you basing your belief that "enlightenment should eradicate neurotic attibutes"? Is it based on something you read or is it based on people you know? If it is theoretical can you explain the mechanics of it, how it works, in detail? Why do you think that should that be true?
I don't want to argue about the definition of "nice", that is why I explained that what I meant is that if you are hard to get along with before enlightenment, you will be hard to get along with after enlightenment. I am basing this on my observations of people who were enlightened who were still thin skinned, deceptive, insensitive, hypocritical, etc... There have been
many sexual scandals involving enlightened teachers and their victims suffered.
A lot of personality is deeply ingrained in the brain: word selection, tone of voice, personal habits, sensitivity to others etc etc. Noticing something about how the mind works can change your perception of your "self", but it doesn't completely rewire the brain you have been training all your life to the extent that it erases your personality.
Theoretically, enlightenment should make one easy going because nothing can hurt your feelings and you don't care what happens to your body because you don't feel like you have a self that can be harmed or insulted or can lose or can own a body, or can have something bad happen to it.
But, the thing they don't tell you until you have spent years meditating and probably a lot of money on retreats, and classes, and meditation cushions and robes and floor mats, and books, and magazine subscriptions, and incense, and voluntary donations, is that almost nobody
perfects enlightenment. So yes even the first stage of enlightenment is a real phenomena and people experience less suffering and it is irreversible, but it is still not what you think.
I think certain types
meditation can improve your personality to make you a nicer person. But that does not require enlightenment. It comes from
changing your brain chemistry not any insight into self. That is what I have experienced.