I think an example to demonstrate my point is when taking a picture with the lens nominally focused at infinity. If you simply focus at an object at infinity, as you describe, then you will throw away a great deal of potential depth of field for the comfort of seeing a maximally sharp image (of infinity) in the viewfinder. From the standpoint of your composition this may be what you want, but I doubt it. I can't think of any simple way of boiling down the process of setting the focal plane of an image that does not come to terms with the near and far points of acceptable focus based on your estimate of the depth of field. Even if your strategy involves setting the focal plane at a fixed distance and hoping for the best, this strategy does not work well at infinity. I do, however, agree that this simple strategy will work if your objective is to maximally render a flat plane, such as the tombstone in one of the original posters portfolio pictures.
I don't describe simply focussing at infinity.
I strongly feel we have to put focus there where focus must be. Focus is a tool used to set the focus of the image we create.
'Hyperfocal', considering the near and far limits of focus, is a technical, numerical appraoch, that fails to acknowledge that the image is about something, instead acts your subject as if it is a distance range.
So we must set focus where it is supposed to be (say, the eye in a portrait - you decide: it can be anything, as long as you decide what the focus of the image you are creating is!), then use the aperture to control how the bit in focus relates to the rest.
There are limits to what you can do with the aperture. But i don't think that is bad: it protects us against ourselves, should we ever feel the desire to make too much part of the subject of our images, letting it drown in indecision.
Nowhere in the process should near and far limits play any role. This is not a mathematical thing you are doing. So infinity or not, it does not make a difference. We shouldn't even think in those terms.
The silliest thing i think you can do, by far (and then some), is to let focus be decided by mathematics. Let the number game, condicence, decide what is and what is not the focus of your image.
So we do not "hope for the best". We carefully and deliberately place focus, and use the aperture to get the image the way we want it to be.
Alll the above is, i think, extremely important. Yet beside the point: when you know what to focus on, it can be hard to decide whether you have it, critically, or not.
Eyesight, as suggested, is a factor.
Yet in the end, it remains a bit of a guessing game. Like anything that we want to do as good as possible.
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