The article says the malnutrition among the inmates was similar to that of the rest of the French population during the war. The 50,000 corpses aren't proof of targeted killing of the mentally ill, unless you can point to figures on how many "corpses" the rest of the French population produced during the same period, and show a per capita discrepancy.
re malnutrition deaths in mentally ill versus "normal" civilians.
The number of civilian casualties in France 1940-45 is estimated between 150 and 350 thousand out of a population of approximately 40 million.
Source:
http://users.erols.com/mwhite28/ww2stats.htm#France so there seems to be an excess of deaths in such institutions suggesting deliberate neglect.
The German T4 project was terminated because of civilian complaints to the government about loved ones being killed, so the Germans also used indirect killing to rid themselves of the mentally ill and retarded...Lifton's book on Nazi Doctors goes into this, as do other holocaust books...