I'm male, and strongly right handed. For most purposes, my left hand isn't much better than a flipper. I'm a ten finger touch typist, and I play guitar (stone-fingered campfire guitarist, nothing fancy), so my left hand isn't completely useless, but it has nowhere near the strength or dexterity of my right hand.
Interestingly, I have a twin sister who is equally strongly left handed for most tasks, except she also plays guitar, much better than I do, right handed. She's also pretty good on the piano, a skill I could never master.
Hmm... actually I have five siblings, two sisters and three brothers. The sisters are both left handed, the brothers are all right handed, but five of the six of us are guitarists, and we all play it right handed.