So, where might ATC fit into this when they pass take-off clearences to pilots of non-public transport single-engined aircraft on days when the weather is clearly below the above minima? Maybe some recommended practices, if not already in existance, might be of use in the future? Just a suggestion.
There's a chance of this tragedy resulting in some positive human factors outcomes, whether in the form of knowledge or regulation. A blurring of the distinction of responsibility between ATC and the aircraft commander would not be one of those positive outcomes. The clearest lesson to be learnt is one about clarity of responsibility.
ATC exists to separate aircraft and manage traffic, with a secondary function of providing information. It does not exist to police the air, nor to provide advice to pilots who have mismanaged their flight.