Maybe because most lenses today are too high-tech. But the tech isnt up to the lenses. Manufacturers have removed lens scales because of auto focus, but haven't developed auto focus techniques to replace what they have removed.
After removing all the manual guides for focussing (no split prism, no dof scale, smaller viewfinders, bigger DOF viewfinders etc) they have left only P&S style autofocus in ALL cameras. But cameras as DSLR's (wich has much shallower DOF, interchangeable lenses and are more advanced in general), even the entry level ones, HAS to offer more advanced focus controls, since you cannot always allow fully automatic operation of such complex task as AF or use manual focus in fast, precise and professional enough manner with so crippled implementation as current one.
As well as you cannot expect a unit to be perfectly compatible in a hard coded/pre configured and fully automatic way with such variety of exchangeable parts having so many possible configurations and different origins. I could only expect it to work more or less flawlessly if each of the device had something like a device driver, but in current configuration it is pretty much a miracle
.
If you take pictures in Av mode, AF would be much faster if it measured a rough subject distance, and if it is within the hyper focal range of the current aperture value just jump to it.
It is hard for me to imagine doing this with DA 18-55, in a day when i'm out shooting only landscapes, knowing how loose the focus ring is in MF and that the lens has no scale.
But it would ensure fast and always correct focus, if camera just threw the lens at fixed position with no unneeded calculations.
I'm still surprised that modern digitally controlled and programmed cameras offer so small customization. They should already long time ago have simple but powerful tools you can use to fully customize and reconfigure camera from PC. Set various calibration parameters, store multiple configurations, fix simple issues, button assignments, menu layouts metering techniques (e.g. kelvin thresholds) and modes. For many years they already use operating systems, up datable firmwares and powerful processing electronics and are far from mechanical or hard-wired/coded machines. Many other tools (as smart phones, computers) at such price levels, complexity already offers functions like those.
Such system would allow the tool to be made for photographer and allow to preserve and have most comfortable operation scheme between different DSLR's they own.
What's the point of software if you still make it hard coded. Just allows for manufacturers to release new camera models without REAL improvements, just functions or minor redesign. But this only makes benefit manufacturers wich release new model every other month. But one with such a joint and backwards compatible system would be truly made for photographer.
I don't mean that users need to write code for motor control, but things like pre definable focusing distance intervals(e.g. Macro 0-50cm, indoors 0.5m-5m, general 0-Inf, landscape 5-Inf), setting timer times and check boxes for mirror lock-up's would seem logical configuration possibilities.