There is pretty much no aspect of this grammar issue that I didn't already completely understand forty years ago (at which time I sided with the prescriptivists, my excuse having been age twelve).

It's perfectly clear why some people don't like "comprised of", and what their reasoning is. That reasoning is seriously flawed, though, on multiple accounts.

The first is that language changes. This particular ship sailed so long ago, that it literally could only have sailed; the age of steam power had not yet dawned. In that time we have seen changes like sensitivity taking the place of sensibility.

Secondly, "be comprised of" follows sound word-forming processes inherent in the English language. It's obeying certain rules, just not ones that are above the sophistication of internet grammar cops. There is no rule that the participial adjective "be comprised of" has to relate to the verb "comprise" in a specific way.