The airline industry has a lot of experience operating around areas of volcanic ash. The closure of the airspace a few weeks ago was an understandable over reaction as those making the decisions were dealing with an unprecedented situation in the UK and Northern Europe. A perfect storm if you like with a volcanic eruption under a glacier, an unusual weather system for the time of year and a our political leaders pre-occupied with an election etc.
What is happening now is a more measured and sensible approach to a difficult situation. As with all such situations lessons have been learnt and systems will now be developed no doubt to better predict dangerous levels of ash in European skies and strategies to manage our airways in a more sensible way.
Anyone who suggests that airlines have been reckless really need to think again, it is not in the interests of airlines or airline bosses to risk aircraft or passengers and such claims are sensationalist. There may be a long term cost due to engine life but that is a matter that I know in my own company has been thought through and a very thorough inspection program is in place.