There are still miners out there with old versions of the software and running the defaults. Thus, if there's not too much of a backlog, it's quite possible zero fee transactions will get included.

So if zero fee transactions are actually a problem, perhaps it is better that we do have a bit of miner centralization so we have professional miners who actually pay attention to what they are doing instead of a bunch of amateurs not acting in their rational self-interest as was supposed to happen.