You're right in that a DJ is many things to many people. They're all of those things to me.
I'll give you my take on it all. For many years I would buy music only on vinyl because of the edits on them, i did the same with cassette tapes and CDs and I still do that to this day. As a hobby, i produce music. It is not a job. I have made very few remixes in my life, I am not good at it, the most I ever do is for fun I will put acapellas on top of any tracks I make just for my own personal amusement.
Nowadays I'm lucky in that I have client accounts with the big labels, don't ask how I got them but what that does is it lets me have access to a lot of music, I can request music when I want it, near enough any instrumental I want, many acapellas that are simply not sold to the public via CD singles, not given out on promos to DJs and are not supplied to online record pools. I have most of the top 40 albums in instrumental form, the catch being most are watermarked and I couldnt share them even if I wanted to. As a DJ will tell you, you can invert them and get a pretty clean acapella out of them. The point I'm making is, before i had these client accounts and I could get entire albums worths of instrumentals and clean edits and every other version you can think of, i relied on the labels sending them out as promos and singles. A DJ promo would often be pressed at a few thousand copies, many ended up online for sale for very cheap, many ended up in high street stores like HMV and Virgin, they didn't mind that. They didn't mind that not only the big DJs, but any DJ, any member of the public had access to them if they wanted to buy them. Now I've spoken to a few people in a few labels and they've told me why not only do they not send out those tracks anymore willy nilly but they also told me why most CD promos now and online digital promos are just one track, just a basic radio edit or main edit and I don't like their excuses. I think if they really supported DJs, they would be putting all those mixes on the CDs and their online sites, they would have made all those edits available so that a wide range of DJS had access to those tracks, instead, they took them away.
I know there are sites that release the stems, I know there are sites where people trade stems and that is a much more creative way to make a mix but it's not for every song or artist, nor was all the promos in the past. What i'm saying is, for chart music, popular music, not that long ago, it was fairly easy to get different mixes for all the big singles which meant DJS, professional or amateur were able to make their mixes fairly quickly and everything they did was current. It just doesn't happen anymore. I suppose it depends what kind of music you are into but if you like chart music, it just doesn't happen anymore. That's what I'm talking about. I'm talking about radio shows where every remix is by DJS youve never heard of but they sound awesome, bootlegs, mixtapes, all the time with songs that are still in the charts, it just rarely happens now and if it does happen it's not because someone at home is talented and did it, it's because a big super DJ has been given the tracks and that's what sells it.
Any oppertunities for newcomers to make their own mixes has reduced dramatically because most of the songs they would want to mix they wouldnt know where to get the acapella from or it wouldnt be available to them or the same with the instrumental or the stems. I'm not say that would have been the case in 2009 either but there would have definately been more options available. Now it's very much a case of private collections and people trading and no one giving out their sources and everyone trying to one up each other and better each other whereas in the past those tracks were just given out and your talent decided if you were good or not.
So for me it's always about the different edits and unfortunately the labels just don't like giving them out freely anymore unless you have good reason for wanting them.