
I'm not really sure that a canopy would work on an F1 car...
As Longbow says "Motorsport is Dangerous". It's on your ticket, its mentioned on the TV and in the print media and hell it's even on a sign at my local kart track (which is in a field... with sheep)
Again I have to side with those against such a measure. Sadly the past few weeks have seen incidents of a freakish nature. Both unprotectable and both unexpected. However you cannot simply cover up the cars, then they wouldn't be a single seater.
Drivers still die in covered Sportcars and tin tops, you cannot escape of reality of death in motorsport. Any measures taken would be a knee-jerk reaction. What happened over the April-May weekend 1994 was different. Motorsport for a longtime was in need of an overhaul in safety. It is just unfortunate that two drivers had to lose their lives for that to happen. At least the safety drive is ongoing at the moment.
Maybe we are too used to drivers ploughing cars into barriers at huge speeds, and then walking away uninjured?
It is sad to say this, but it is the truth: Sometime in our life time there will be another fatality in Formula One. I know it is awful to say that, but it is true. You can never cheat death! You can try and protect the driver's head as much as possible, but what if in this period a driver dies in another way? Do you just drop tools and folk over to improving that area? You cannot keep up with these things, sadly life isn't like that

That shouldn't mean that steps aren't take to continue to improve safety for the drivers, spectators, pitcrew etc - for it lessens the chance of fatality.
Sadly nothing could have prevented Massa or Henry Surtees from being struck. The object was head on and at speed. It is just something we have to accept in Motorsport.