This is art-school grade circle jerking. The author seems to conflate the words "mixtape" and "mix tape". Mixtapes are not an alternative to releasing albums, they are a way of artists exploring their music and sharing it with fans in an informal way that leaves them more creatively open because you can't easily get sued for using an uncleared sample if you're giving the mix away for free. Notice that all the people he quotes who have actually researched the matter use "mix tape" not"mixtape".
In fact, my credit card is designed to look like a mixtape.
Pass me the fucking bucket you insufferable hipster.
PS: I miss mixtapemixtape.com it's on archive.org but without the mp3s, so you might be able to track them down using the filenames but MAN was this a great resource for pomo mixtapes.