I have never heard of a ‘Desmond’ being converted into a 1st by taking a masters. Of course if you are an Oxbridge person then your bachelors will automatically be updated to a masters as long as you do not blot your copy book.
I am in academia and I can say that it is possible to be able to enter a masters course with a 2:2 but the universities that will accept that approach are not viewed by employers as being in the top tier.
Two of my degrees are from Red Brick Universities and they would not allow a 2:2 into a masters course. The strong element of research needed would debar them.
However would not wish to post in such a way as to deter people below a 2:1 from a masters so may be if they were to undertake some work experience then maybe an MBA would be appropriate. If not, then a masters after completing a professional qualification, would be a good option as a better grasp of, and approach to study, will have been developed.