Yes, it is. It's a state law, and it's illegal in Florida (and many other states). The passing of the law doesn't stop it if people want to do it. Maybe we can ban cell phones because of it?
Mexico homicide rate much higher than U.S...6.34 vs. 3.43 (Wikipedia)! The U.S. has a much higher suicide rate...go figure...the country with more wealth.
And I'm sure all firearm deaths are reported. That's the ticket. Mexico, with all it's cartel violence...the cartels are using nerf guns.
The point is, it's still a big problem. The people who want to do it, do it. The law isn't their concern. Safety is, and you could have accomplished the same improvement with increased awareness. I'll bet states that don't have the law saw increased safe driving as well.
Even with the numbers under reported: http://www.gunpolicy.org/firearms/region/united-states Rate of All Gun Deaths per 100,000 People ChartIn the United States, the annual rate of all gun deaths per 100,000 population is 2014: 10.5420 2013: 10.63 2012: 10.69 2011: 10.3820 21 2010: 10.2620 2009: 10.22 http://www.gunpolicy.org/firearms/region/mexico Rate of All Gun Deaths per 100,000 People ChartIn Mexico, the annual rate of all gun deaths per 100,000 population is 2014: 11.2316 2013: 13.57 2012: 15.86 2011: 18.04 2010: 17.96 2009: 13.04 So no, they don't have a lower firearm reported death.