OP here: I rescind my statement. Up until now I had never seen a piece of fiction I hated vehemently enough to apply discontinuity to it... however, I have recently read Mockingjay, and I totally get it now. It's still pretty dumb, though.
Mockingjay wasn't that bad. Vastly weaker than the first two, certinly, but not bad enough to justify completely ignoring it.
I take the point that a lot of the main article reads as "I'd like to take the opportunity to complain about this!" couched in the language of "some fans" (read: me) "like to pretend this never happened."