Those are 2 very different questions.
As for the first…consider also where he came from and the greater context of what he was saying. Disco has live drummers. Live drummers groove (or sometimes just suck at keepng time). Without warping the tracks, it’s damn near impossible for a mix to be perfect.
I’ve heard somebody do it once. He was spinning an 80s night at a local bar/club, and he’d been doing it since that music was current. He’d played those records thousands of times, and he knew them well enough to ride the pitch…because he knew which tracks had drum machines and which ones had live drummers…and how the drummers played, when they dragged behind, when the pushed…it was an impressive thing.
I couldn’t mix like that. Then again, I also coulnd’t mix the same 100 or so records every week for 25 years, either.
So, taking that into consideration, I think there’s a limit. A night of all trainwrecks isn’t good. A drift here or there…meh. But, if it’s possible for you to be perfect (e.g., if you have a sync button) and you’re not, I kind of just think that’s disrespectful to your audience, the party as a whole, and the music. It screams “look at me, I’m not using that new-fangled technology and this mistake is proof…applaud my mistake!”. It puts you above the music when it should be your job to put the music first.
If you’re spinning disco with vinyl, there are going to be some stray hats no matter how good you are. If you’re spinning techno with traktor, there won’t, no matter how bad you are.
As for the focus…it should be on the music. Booze gives people something else to appreciate (if it’s crafted well, which is rare in clubs), and booze/drugs (if you’re into it) can help people enjoy something that they might be too restricted or self-conscious or closed-minded to enjoy without it.
I’ve seen (heard?) some fantastic DJs. And universally, the ones who either looked like they were enjoying themselves but also concentrating were the best…the ones that acted like the center of attention…were the center of attention…and the party suffered for it.
Play the right track at the right time and your job is 90% done. Don’t ruin the groove by mixing it well (the track will tell you how it wants to be mixed) and avoiding trainwrecks, and you’re 99% there. The last 1% is up to you if you want to do something “special”, but make sure it doesn’t ruin the rest of the work you put into it.
And after 10 years of doing this mostly for myself, at a handful of successful parties/events, and a few not-so-successful ones…picking the right track is still the hard part. It always has been, and it always will be.