If you read the whole article, the author mixes in caveats throughout and says that it requires a special set of requirements for the usenet backup to be worthwhile. At some point, he addresses your point by saying that in some cases (possibly requiring careful coordination between all of the servers) you could backup many different servers with the same usenet account whereas services like Backblaze and Crashplan usually restrict the number of machines.
That said I still think the point you make is the most important critique. Online storage/backup is such a crowded market (Google, Amazon, DropBox, Box, Backblaze, Crashplan, Carbonite, Mozy, tarsnap, Spideroak, rsync.net, OneDrive, etc) that if you go with something significantly cheaper than all of the mainstream options you are probably going to get what you paid for.
That said I still think the point you make is the most important critique. Online storage/backup is such a crowded market (Google, Amazon, DropBox, Box, Backblaze, Crashplan, Carbonite, Mozy, tarsnap, Spideroak, rsync.net, OneDrive, etc) that if you go with something significantly cheaper than all of the mainstream options you are probably going to get what you paid for.