As much as I do like a well-developed Companion, they are diametrically opposed to my preferred play style. That is, sneaky sniper. I can't count how many times I've been creeping along and then out of the blue my Companion will open fire on a foe I did not see, scaring the beejeezus out of me. Yes, she saved my life (arguably) but it's still an ~unexpected~ engagement. And then there's the companion kicking over cans and what not. And just BEING there. I mean, I like to be ALONE while I stalk the wilds with my trusty sniper rifle. With a Companion --- especially a "good" one that comments on the world and isn't just a silent pack mule ---- I almost feel obligated to pay attention to them. Just my loner nature, I guess.
Unfortunate or fortunately, the Companions are too good to just leave behind. That's one thing that always grates on me with New Vegas --- the companions are so good, and have their own stories and such, but they are triggered by visiting locations or being involved in gameplay, not just sitting in my base waiting for me. So I want to have them with me to expand their stories and hear their dialog.... and yet I also want to be ALONE. Things would be so much easier on me if they were "bad" companions, just silent meatshields and pack mules. I still wouldn't USE them, but I wouldn't feel as bad about NOT using them.