I still feel it is an overreaction. Yes, it is unsafe to fly inside a volcanic ashcloud, we've seen the flameouts and damage.
Yes, it is wise to avoid flying into severe concentrations of the stuff and it is wise to have a safety margin.
But a total shutdown of aviation? Without any scientific debate on concentration levels and dispersion?
It is akin to the world wide panic over all sorts of supposedly lethal flu strains that caused nothing more than a ripple in the illness levels, yet caused a lot of stress and a huge strain on health services.
I'm afraid the "better safe than sorry" attitude does not cut it. Because the apparently safe decision may and will have unforeseen aftereffects that may be quite detrimental to safety levels. Like a lack of trust in the next stern warnings. One can only shout "wolf" so often before it becomes ineffective.
Solid particles in the air do nothing to improve engine and component life. But why the panic? Why the shutdown of a large part of airspace? What defines the boundary of safe vs unsafe sky? It is all too fuzzy for my liking, too much "we know what is good for you so don't ask awkward questions".
I am not convinced that it is not a huge overreaction. I would love to be convinced otherwise, but doubt it will happen. We are becoming so docile with the constant war on terror that numbs the mind, takes away liberties and destroys critical thinking that this goes virtually unchallenged..