... and you're in the small minority with that. The "____ presents" is a marketing tool to draw attention of those who know the artist/label presenting (which have a larger name recognition) but are completely unaware of the actual artist doing the album. People see a Big Scoob album, they're going to think, "Who's this random guy," but by sticking "Tech N9ne presents" on there, Tech's casual fans will see his name and perhaps be interested in it, even if they have no clue who Scoob is (for those who don't bother with samplers, and don't stay up on Strange Music as a whole)
This especially goes for Retailers. They may know that Tech N9ne sells, but not have faith in another album from the label if they don't recognize the artist. Putting Tech's name on it may increase their faith in the success of the album, and thus order some copies to stock, instead of skipping it. Furthermore, this means it (should be) organized in the Tech N9ne section on the music racks, which increases the possibility of those semi-interested in Tech and thus (possibly) semi-interested in this album, stumbling across it.