A thoughtful and reasonable rephrasing of the OP.
The only point I’d disagree with here, perhaps, is what constitutes “the vast majority” you cite as “decent and competent professionals.” From my perspective, that majority is (let’s pick an arbitrary but accurate estimate) 97% of lawyers, cops, physicians, etc. Of the remaining 3%, I’d guestimate that about .05% get caught committing ethics violations, and fewer than half of those get punished in a way that affects their lives severely.
That said, and forgetting about the specific figures I just invented, there are those in this thread, I believe, who insist that I underestimate the percentage of ethical practitioners, and underestimate the percentage of violators caught and punished. These apologists for the self-regulating professions, such as Princester and Northern Piper, seem to think that there is no such problem in the professions at all, and it is being very well regulated, if it exists at all, by the professions currently. It seems to me there is a large difference of opinion here, between them and people like Jackmanii and myself as to the extent of the problem and the effectiveness of the regulations. Perhaps the strongest evidence for my side of the argument is the low regard the public has for most of the professions. If the law, for example, were regulated well according to the highest of ethical standards, would most people think of lawyers as the unethical sleazebags that most polls have told us they do? Is it reasonable that this perception is entirely due to sensational fictional TV shows and none of it is due to the ethical lapses they can witness happening in real life?
If we want to put numbers on it, I’d say