Someone said :
Yes, but that is a balanced 'nice'... I think being too nice involves giving more of yourself because you feel you have to/should/need to, with less regard for yourself and how it might be impacting you...... some would call this unselfish, I think it is often selfless, which is different and damaging to oneself. (imo)
It depends I guess on your thoughts on exactly what being nice means..
I could open a door for someone, pick them up if they fall, help someone cross a street, that to me is being nice...
When it extends to having to constantly help or make others feel good, then either they are too needy or you are, as in the martyr syndrome..