As far as I'm aware, ash has never caused the loss of one airliner. Birds on the other hand bring them down a fair bit. But we don't stop flying because a weatherman saw a couple of ducks in the air.
If there is no problem than it won't be too difficult to persuade the manufacturers to loosen their guidelines then, will it?
I have no problem with solid evidence based decisions, but referring to the situation as a farce and blaming the 'authorities' for what is fundamentally the airlines own rules is ridiculous.