[1] http://www.cdc.gov/injury/wisqars/pdf/10LCID_Unintentional_D...
The law could really just affect swimming and driving. Both activities are common and can result in death if you're not careful.
I did it once, because it seemed natural to look at the person I was talking to, but I immediately felt endangered and have never done it since.
Whereas with the inaccurate portrayal of drowning response, by the time you've realised that what you're doing is wrong somebody is dead.
[1] http://www.cdc.gov/injury/wisqars/pdf/10LCID_Unintentional_D...