My guess is DM brought everything to the party knowing many patents would fall by the wayside...for one reason or another.

It's the same strategy used in most civil litigation. If your fellow employee drops an anvil on your foot, you sue him, your employer, Home Depot, the anvil's manufacturer, the company that mined the iron ore, the country of origin and even yo mamma......if you can establish parenthood.

Just think of it as a sawed-off litigious shot gun. :>)