Can we see your source for this statement?
You have to realize something about Florida. This is the land of invasive species. Just because you heard some news reports about snakes doesn't mean they are doing more harm then a specific fish. Plenty of invasives are so common that people don't bother talking about them anymore. The reptile front has gotten some new additions so it is getting more attention now (especially since stories about snakes killing alligators started). But you don't hear anyone worry about the Brown Anole, since it is now considered "the common lizard" (it turned the rather common Green Anole into a relatively rare find). You don't hear anyone talk about Curly-Tailed Lizards anymore since they are becoming the new "common lizard". The past few cold-spells took care of the Iguana population (for now) but before that people were rounding them up and killing them. The Cuban Knight Anole got some minor attention but the cold-spells seem to have taken care of their population. On the fish front, just about everything has been invasive so long people don't talk about them. The only thing really getting attention is the Lionfish since it is a fish eater. Doesn't mean the other invasives arn't doing any damage though. Or that the snakes are doing more damage.
Dude, if constrictors weren't an issue, it would still be legal to own them in FL.
http://www.venom-center.com/forums/index.php?topic=3684.0
http://jacksonville.com/news/florida/2010-06-30/story/several-new-florida-laws-take-effect-thursday (senate bill 318)
http://www.fort.usgs.gov/products/publications/pub_abstract.asp?PubID=22762