I've been meaning to get around to commenting on this. As you already know, I'm from Florida and Lionfish were a huge issue in Tampa Bay as well. My uncle actually had one in his saltwater aquarium! They're truly beautiful fish but as you pointed out, they're deadly and an invasive species to boot. There are actually many anglers that take the time to kill as many Lionfish as possible for the reasons you specified above. There have been some creative strategies to accomplish this. I wanted to share this video with you:

This guy is from my hometown Bradenton, lol.