I’ve been guilty of it in the past, but thinking about it it’s probably more what Toni said, it’s the ability to resolve detail.
These days it’s far more about rendering, does it have depth to an image, does it have nice bokeh, is it too clinical etc etc.
I look back at some of my Olympus images and they look “too sharp”, but it’s not sharpness really as the detail looks soft when you pixel peep, but somehow they have a kind of harshness to the images. I can’t quite put my finger on it, but it’s also how I feel sometimes when looking at images taken with the Sony 55mm f1.8