My main "reward" by running a zero fee node, is that WE FUCK THE BANKSTERS. Once we've done with that, we can start creating an incentive way to run these nodes and not ripping off users.
Like @arrowdrive said, sometimes is much efficient to do a tx onchain than LN. This is just stupid and in special in this phase when we need to onboard as many people we can into LN and make this network to flow a lot of liquidity.
I start in Feb with the "#ZeroFeeFebruary" movement and from then my node increased 10x the number of routed txs. I even wrote an article about that, for each month. And many other users contacted me (and post replies to my article) and thank me for this initiative, their nodes start moving way more txs than before.
I am in contact also with some users from El Salvador, helping them to run their LN nodes. And they tell me: people there are interested into transacting cheap as possible, but sometimes they get ripped off for a simple payment to buy pupusas. And they move away slowly from using LN. IT'S A SHAME that for some sats earned by routing people get so obsessed into "earning sats with routing", their greed grow more and more.
As I said, now in the beginning is time for helping each others NOT TO FUCK EACH OTHERS. Later it will come the time for earnings...