"Medieval" a Pejorative?

A quick summary of some of the massacres, slaughters and ethic cleansing in the twentieth century:

1.5 million Armenians (1915-23); 7 million Ukrainians (1930s); 6 million Jews (1933-45); 2 million Chinese (1937-45), 30 million (1966-76) and  6-8 million in Chinese slave camps; 250,000 Hiroshima and Nagasaki (1945); 2 million Nigerian Ibos (1967-70); 1.5 million Cambodians (1975-79); 150,000 Iraqi Kurds (1988); 200,000 Bosnian Muslims (1994); 800,000 Rwandan Tutsis (1994); 200,000 East Timorese (1967-96); 500,000 Ugandans under Idi Amin Dada (1971-1979) etc.

Compared to these numbers, civilians killed during the Middle Ages would today be "collateral damage." Dare we use the word medieval as a pejorative?

To describe something as backward, murderous, torturous or insane, better to say, "It is so twentieth century."