To a degree ,the manipulation of photo content has been a problem since photography became mainstream, and, even when it was the provence of a few knowledgable souls, certain folks of dubious ethical orientation were not above "pulling a fast one" if there was economic incentive or publicity to be gained. An excellent example is the famous Civil War photo of the dead Confederate infantryman taken in the "Devil's Den" after the battle of Gettysburg.....it is acknowledged that the body and Musket were carefully posed for "effect"....
The epidemic of manipulated images by so-called professionals, for no other reason than to gain economic advantage or personal recognition is, as you say, threatening to seriously damage the creditability of anyone who engages in Restoration/Conservation or photography in general.
There is no way to totally halt abuses. Some folks simply do not care and will do as they please, ignoring the consequences of irresponsible action. Others will insist that there is nothing wrong with altering a photo to fit their conception of what it depicts.
Its a serious problem. Consider that all the models who appear so vivacious and perfect in Ads are images of people so grossly retouched as to remove the resulting image from the realm of reality...and consider the resulting problems , especially as regards young women who feel that if they dont look like these "Frankenpictured" digital freaks there must be something wrong with them...and the resulting semi-starvation and so on these impressionable people put themselves through as well as the mental degradation, trying to look like something which never existed and never will, causes untold suffering.
Professional orginizations are one way to help maintain and/or restore creditability, but in the end it is a matter of personal choice and a sense of responsibility which really matters...unfortunately today both seem in rather short supply. When I see major Newspaper and news service personnel, folks who are suppost to be Professional, using image manipulation to not just "enhance the dramatic content" but in doing so actually create a totally false impression, it leaves me with a rather sick and disgusted feeling....Tom