I don't use EVOO in cooking because it's expensive, and cheaper alternatives are better in my view in terms of smoke point etc. Olive oil is unsaturated which means it's thermally unstable. Even below the smoke point, it is being chemically altered (mostly oxidation). That degrades the quality of the oil, in effect. This is why one should store it away from light and heat.
I don't think there is a health issue with using it at high T. The "olive oil lobby" tells everyone it's OK to use in cooking, and it is "OK", just expensive.