Actually there are many who love to spear lionfish, and when possible, eat them. The problem is that so many dive destinations in the Caribbean prohibit spearfishing, including for lionfish.
A number of countries have begun to allow it and lionfish killing competitions and barbeques are quite popular where they are allowed. Not a lot of "sport" in killing them, I suppose, but it is popular nonetheless.
Of course it isn't a solution to the problem, but it cuts down the populations a little.
Yes, I think the lionfish round-ups they have from time to time are a great idea. But how to, excuse me, sex it up a bit? Offer prizes? Awards for the biggest, most caught, etc? Are braggint rights enough?
It just seems like the Hemingway factor is missing--we need to see some published accounts of intrepid hunters conquering their most innermost fears as they went mano-a-mano with the dreaded lionfish, a terrible brush with death, and then--aha!--victory! Something like that.
I get why so many places (Bonaire) don't allow civilians to spearfish their lionfish--I guess they are afraid that these unknown civilians will start killing other fish or that accidents will result. But they for sure need a better system then they have right now. Like I said, I was pleasantly surprised by the low numbers of lionfish we saw in Cozumel in March.