First up, I stand by my earlier comment that if someone tries hard enough, any character from any minority/oppressed/not-white-straight-and-male group can be demonstrated to be the product of appalling bigotry on the writer's part. However:
What do you mean by bitch? In a society where women have to wield power through others (almost all pre-modern societies), you end up with the power behind the throne figure (Circe Lannister is the most modern variant), which is a version of The Manipulating Woman, who is traditionally devious and twists honourable men with her wiles, etc. I can imagine this being done perfectly decently, though (Elizabeth 1 comes off as well as someone in those days could), so I don't think this sort of character has to be overtly nasty.
"Snappy" seems to be a standard trait for a woman who does her own thing (the trendy expression is "has agency"). Unfortunately, it tends to make characters look vicious and embittered, and hence weak-seeming. Likewise the female characters who have to have a condition - Aspergers and the like - to absolve them of needing female characteristics, whatever those may be. However, ruling out robots with boobs, there is a huge range of personality types available.
I've written two female characters who I think are pretty good, and two others who are caricatures, but not in the usual way, and work in themselves. I'm pleased to say that they're all quite even-tempered, although the one closest to the stereotype - an attempt to write the thief/assassin stereotype as something other than a male fantasy - had a rather broad depressive streak. None are cruel, although two are really quite bloody.
Of course, without looking into too many dark places, there's the sexual aspect. I do think that if you are going to write good characters you have to be absolutely clear about whether you are going to write a real person or some sort of pin-up, and the reason so many "empowered" female characters feel the need to become empowered via a leather wetsuit and a whip says a lot about the writers (and pretty much de facto makes them rubbish characters). As an aside, anyone who enters battle in either underpants or high heels has a swift, brutal death coming.
Personally, in order to keep away from the "bitch" label, I would avoid impractical outfits, overt bad temper, treating all men like infants (Eddings!), disliking other women and anything suggesting sexual oddity. Oh, and doing anything seductive to get one's way really makes a character look cheap. There was a thread a while back criticising the Wheel of Time for its females - it might be worth searching for "Wotism" on the forums.
EDIT:
and here it is:
http://www.sffchronicles.co.uk/forum/11424-lets-coin-a-new-term-wotism.html