The problem dragonwriter was moving towards pointing out is that, for example, if the active voice version of a sentence is "John eats food", then the passive v

The problem dragonwriter was moving towards pointing out is that, for example, if the active voice version of a sentence is "John eats food", then the passive voice version would be "Food is eaten by John", not "Food is eaten of John". In the same way, active voice "Interesting people comprise the majority of the Wikipedia editorial community" would have passive voice analogue "The majority of the Wikipedia editorial community is comprised by interesting people", not "The majority of the Wikipedia editorial community is comprised of interesting people". You claim that "B is made up of A" is a passive form of "A makes up B", the preposition being chosen to match the semantics. I think this is incorrect. The preposition used to introduce the agent in a passive construction is always "by"; "B is made up of A" is not the passive form of "A makes up B", but rather, the passive form of "__ makes up B of A" with agent omitted. Analogously, "The soup is made with love" is not the passive form of "Love makes the soup" but rather the passive form of "__ makes the soup with love". (More examples: "Cereal is eaten with milk" is not the passive form of "Milk eats cereal", but rather, the passive form of "__ eats cereal with milk". "Tea is drunk at noon" corresponds to "__ drinks tea at noon", not "Noon drinks tea", and "Tea is drunk in the kitchen" corresponds to "__ drinks tea in the kitchen", not "The kitchen drinks tea". And, for examples using "of": "John was relieved of duty" is not the passive form of "Duty relieved John", but rather the passive form of "__ relieved John of duty", and "Lance was stripped of his medals" is not the passive form of "His medals stripped Lance", but rather the passive form of "__ stripped Lance of his medals". "The dreidel was made out of clay" is not the passive form of "Clay made the dreidel", but rather the passive form of "__ made the dreidel out of clay", just as "The dreidel was made out of clay by me" is the passive form of "I made the dreidel out of clay". Etc., etc.) I would say this scuttles your claim that what is going on here is simply an active to passive voice switch, even though I think I am of a different mindset than dragonwriter as to the acceptability of the construction of interest (I'm perfectly fine with all the ways people find themselves naturally using "comprise", as I am in general a staunch descriptivist. I just happen to also think you've mis-described the syntax of the English passive voice construction.).