Why does the question matter?
I would say yes (assuming they do live perfomances and don't play pre recorded sets...) but the skill level is nowhere near what it takes to play an instrument or compose quality music.
All depends on the DJ. the skill level could be beyond what it takes to play an instrument, and some cases there is no skill level.
I didn't catch that since I didn't really go through the thread. I'm of similar mind.
I don't blame you for not going through the thread, it's brutal.