Right.
Disco lyrics are always bland and the beat is repetitive (and rock lyrics most certainly never are).
And rock instrumentals are always a bad thing.
Got it.
Really? That’s your argument? “I found one disco song with a lyric that isn’t about dancing (but which even so still has that boringly repetitive disco beat), and I found one rock song that has a repetitive chorus (even if the rest of the song features non-repetitive lyrics)”?
That’s all you’ve got?
Hardly.
Good disco songs: “Knock On Wood”, “Night Fever”, “Don’t Stop Til You Get Enough”, “September”, and “Don’t Leave Me This Way” (among many others).
Crap rock songs: “In a Gadda Da Vida”, “The Living Years”, “Tones Of Home”, “Walk On the Ocean”, “The Loco-Motion”, "Point Of Know Return’. (Really, I could go on. And on. And on, even.)
Dude, I’ll concede the point if you’ll promise to stop dredging up horrible videos from the disco era. 
And I’ll renew my assumption that thinly-veiled (or maybe not-so-thinly-veiled) homophobia and racism has an awful lot to do with knee-jerk, out-of-hand dismissal of disco (and dance music in general). Dude. 
Q.E.D.
Hey, while you are assuming, why not assume you are a billionaire? If you are going to indulge fantasies, pick a good one!
One could argue there is still good disco music being created today:
(Okay, you need to have played WoW to fully appreciate it, but the song is still awesome)