She was a woman with an attitude who got to where she was by working hard and not giving up.
Then, this guy comes into her life who outclasses her and stymies her in every way, but is also crazy hot and awesome.
It frustrates her to no end, and then a machine comes along that almost literally magically makes her as powerful as he is at the cost of her sanity and humanity.
Well, I mean, she wasn't completely crazy or nothin' but she did become half-Kree with a split personality.
And from then on out, in spite of her amazing powers, he life basically became a series of unfortunate events. Carol was almost the quentessential Marvel hero: it was just one shitshow after the other; if it wasn't one thing it was the other.
And really, that never changed. She was just moved to the forefront and a lot of people didn't like it, even though it makes sense.
But as a person, she actually is kind if bland, because she is not a natural weirdo. But then, neither is Peter Parker.