So what sports do you watch?
Do you watch football, a game in which a game with no player being injured is considered a miracle and broken bones are commonplace?
Do you watch rugby, which requires full-body contact as a key part of the game?
Do you watch American football, which is so bad the players have to wear armour?
Do you watch horse racing, where jockeys frequently end up injured, to say nothing of the horses?
There are associated risks with every single sport, no sport can ever be 100% safe. Motorsport has come a long way forward in terms of safety; there have been a number of crashes in Formula One in the last few years alone that 10-15 years ago the driver wouldn't have had a hope of walking away from. (I'm thinking Webber and Kubica).
Motorcycling in particular there is the danger of the person becoming detached but they still have other forms of protection like the whacking great helmet that in Marco's case tragically became detached, and that's what you're forgetting - both Marco Simoncelli and Dan Wheldon were the victims of tragic accidents. They died doing what they loved, but they still died far too young, and should be missed - not have the sports they gave their lives to criticised for "not doing enough for safety", when there are certain things you simply cannot prepare for. If this **** happened every race you'd have a point, as it stands you just sound like a five year-old who hasn't been told how death works.
Now either get some respect or get off this board.