Well said,
noblepa. Sometimes we want total sharpness, and sometimes we don't, and either can be achieved with lenses selection and careful use of focus and DOF. Using a lens at its soft spot is rather like using a cheap tele or a flawed lens with notable character -- the content is more important than the resolution and details. I don't use my FA50/1.4 or Tomioka 55/1.4 or Tak-B 135/2.5 or various other glass wide open when I want maximum detail -- I use them when I want the subject to leap from the frame.
And that is why I use all sorts of non-camera lenses (enlarger, projector, meniscus, etc) on bellows, because I can obtain effects that aren't obtainable otherwise. Something I just found today: Take a Raynox DCR-250, which is a +8 dioptre. Put a +2 dioptre 49mm screw-in on its front threads. Put a 42-43mm step ring on its base; mount that on an M42 bellows; mount that on a dSLR. Hey, now it's a soft 100/2.5 lens! The centre is somewhat sharp, all else is soft and lucent, a nice setup for dreamy romantic portraits. And I don't even have to pull up a Pastel filter in PP!
Lenses in the f/1.4 neighborhood, no matter the focal length, are sophisticated tools. A bit of training and practice are needed to master them. Oh Goddess, not
another learning experience!