I'm not a huge fan of the Funkmaster Flex series of mix sets because of all the vocals overlayed by him throughout--the mixing and scratching isn't all that bad though. But I don't know if it's exactly right to say he's not a DJ because he's not remixing each track. Yes it's more of a compilation than a smooth mix, but it kinda goes with the music he's playing on it. I haven't heard much of DJ Clue, but from what you're saying, it's probably about the same.
You're right, anyone could put together a similar set, if you had the equipment and skills that they have on the tables. They also have the fame, which helps the sales of the CDs to people who don't know much about the records.