This won't be a surprise for anyone who knows much about him. Mark Mothersbaugh was a punk/new wave guy (though obviously not exclusively) and most punks had a visceral hatred for disco.

> The earliest known live performance of the song was on Halloween night of 1975, opening for Sun Ra.[3] The released recording of this version is seven minutes long.[3] However, according to a 1997 interview with Mark Mothersbaugh, they performed a half-hour rendition of the song as a joke to annoy the crowd: "We'd play 'Jocko Homo' for 30 minutes, and we wouldn't stop until people were actually fighting with us, trying to make us stop playing the song. We'd just keep going, 'Are we not men? We are Devo!' for like 25 minutes, directed at people in an aggressive enough manner that even the most peace-lovin' hippie wanted to throw fists."[4]

Edit: here's the audio only version: https://www.youtube.com/watch?v=82j12E3cpS4

It probably looked something like this: https://www.youtube.com/watch?v=Gcp8osYmU88