But from my perspective on the ground, there wouldn't be much point in you commencing an approach if the cloud base was below the DH minimum for the category of approach that you are flying - thereby precluding the probability of achieving the visual cues required to complete a landing.
Not true - the AOM are well constructed such that if you have the required RVR it is highly likely you will have the required visual reference at DH in order to continue the approach to a safe landing. CAT 2/3 lighting will punch through a hundred feet of cloud. I have done many instrument approaches (CAT 1) where the reporting vertical vis was 100 ft and have acquired visual reference by or even before 200 ft.
Also there is a difference between cloud base (the lowest cloud) and cloud ceiling.