Really hard to see how someone can "doubt that Senna or any other F1 driver who lost their life to the sport would wish to see F1 stripped of it's thrills and challenges in the name of safety."
I would have thought that if a dead race driver could talk to us one of the first things they would ask would be to try and make sure that what happened to them will not happen again to someone else. And that's probably the best thing we could do to honour their memory.
Times change, and thankfully safety standards change as well. Motorsport is always going to be dangerous, but it is the FIA's duty to ensure all necessary measures are taken to reduce the possible risks to the degree possible with all the means available.
I'd much rather have a historic track layout changed - ideally without changing its character too much - than risk having more lives lost in vein. Just think of how many drivers had horrific accidents the last 15 years and just walked away with a few bruises. We could blame FIA for many things, but with regards to improving safety standards I think they have been doing a damn fine job, and I hope they continue doing just that.