You seem to be implying that PicMA should be used on all flights, but isn't it actually only needed in bad weather?
It's true that most people associate PicMA procedures with specific weather criteria (cloudbase and visibility RVR). That certainly mitigates a lot of risks. However many accidents involving poor planning and management, many involving breakdowns of monitoring, and many cases of descent below MDA without visual reference have occurred when none of these criteria were met.
These criteria rely totally on the assumption that weather reported to crews prior an approach is what will be found by that crew on arrival at DH/MDA. In fact nothing can be further from the truth - weather reports can be grossly misleading. Accident reports show that on a very high proportion of occasions the crew were completely taken by surprise by the conditions especially vbisual cues, they found.
Standard Procedures should prepare the crew to cope with the worst case even if it doesn't arise. Having a good procedure available, and crashing because you didn't "need" to use it is unforgiveable, but is actively encouraged by employing such restrictive criteria.
Secondly, having it as a "bad weather" procedure means that it is not practiced on a routine daily basis. Crews become habituated to doing things differently to that needed when perfectly predictable but not everyday circumstances occur. Using PicMA as a single procedure in all conditions ensures that crews are completely practiced at it and fully familiar with all aspects when the need is strongest.
The use of PicMA on all appraoches forms a safety net against many threats that are well known and routinely occur.