IPv4 address space is in short supply, so some people decide to use IP space ( allocated, but not advertised) that doesn't belong to them. The consequences are pretty well described in the article you quote.
But this address space is non-routable, so it's effectively using address space that's equivalent to a 10/8 or 172/12 or 192.168/16 address. There's no need to grab random /8s when there is plenty of IPv4 address space that won't ever get routed to the internet (assuming nobody does something as dumb as actually changing the 127/8 semantics). If they somehow run out of those, 100.64/10 is also pretty much guaranteed not to be reachable from the internet.
