Every feature even when deactivated has a cost: poorer ergonomic design, compromised de-activated function (I'm thinking particularly of the dismal viewfinders of AF cameras) and each feature is is an opportunity for Murphy's Law to rear it's famous head.
This is a fallacy. The way it works according to economic reality is: the more features, the more attractive the item becomes to the public at large, and the more units are sold. As a consequence, the cost becomes lower or the quality becomes higher at the same cost. Just because you personally may have no use for a particular feature, does not mean that no-one else does. For example, I never shoot in jpeg mode with a DSLR. However, I don't find the option to shoot jpeg a disadvantage in any way, nor do I think such an option could contribute towards camera mal-function.
However, this is not always the case. A particular feature which puts more stress on a mechanical component in the camera may contribute towards its mal-function. For example, after about 100,000 shots with my Canon 5D, the mirror fell off. I don't believe this was due to the actual quantity of shutter actuations but due to my frequent use the 'autobracketing-of-exposure' feature which causes the mirror to flip up and down rapidly 3 times at each press of the shutter button.
If you had no use for such a feature, preferring an accurate exposure reading from a hand-held Weston, as Rob does, then your mirror is not likely to fall off as a result of
not using the autobracket feature.
Have you ever tried focussing using live view with an active subject?
Any type of accurate manual focussing with an active subject is difficult. Autofocussing is a relatively modern feature in cameras. I renewed my interest in Photography about 25 years ago with the purchase of the first autofocus SLR, the Minolta Maxxum 7000. I later switched to Canon because of another great feature, Image Stabilisation.
Which is exactly why I favor a good optical viewfinder over AF or live view.
Please enlighten me. I've never heard of any optical viewfinder that is a patch on the Canon LiveView system, provided you are able to use a tripod. (A monopod might be too much of a compromise).
The image on my 50D LiveView screen can be magnified 10x for the most accurate of manual focussing. That means, in effect, when you are using a 400mm lens that fills the screen with, say, the body of a bird, you can magnify the scene 10x which is equivalent to looking at the bird with a 4,000mm lens. It's eyeball fills the screen. Whether or not the bird will sit still long enough for you to accurately focus on its 3rd eyelash to the right of its left eye, is another matter. (Okay! Birds may not have eyelashes. Could we say they have eye bristles? ).
If you're obsessed with resolution you might be better off eschewing AF altogether.
If I were very obsessed I probably would, but I'm only a bit obsessed.
It would be absolutely useless to me. For the 1/10 of a second a bird's posture is what I want, I want accurate focus. Not accurate focus on the exposure before or the exposure after. Accuracy beats spray & pray.
Now! now! Doug, I can't believe that. First, there's no exposure before, only exposures after. The shot which is a fraction of a second immediately after the one envisaged (or the second or third or 4th or 5th one after) might not only be the perfectly focussed shot, but the preferred posture and composition. Some of the greatest shots in the history of photography have been fortuitous accidents
Nevertheless, irrespective of whether or not one's camera has the feature of autofocus bracketing, one would like the camera to have as accurate a focus as possible on that first shot. As far as I know, absolute auto-focussing accuracy does not exist, but manual focussing of a 10x enlarged image on a high resolution LiveView screen is the next best thing.