The point is that that is a stupid reason to acquit someone of murder. Perpetrators should not be allowed to attack people, then prove innocence on the grounds that their victims tried to defend themselves. So, why does Florida sanction such stupidity?
The law used to require people to avoid conflict. Now, it exonerates them from legal responsibility for the outcome of conflict.
That's why SYG is often called the "Shoot first, ask questions later" statute.