I wonder how easy it would have been to destroy a large (110x55m) temple, without explosives or even paraffin? Weren't those things made of stone? It's actually quite an impressive feat, in its way.
The online Encyclopædia Britannica refers to Herostratus as a "madman", which seems harsh. At least, it's a very common form of madness - the last infirmity of noble mind, as Milton put it. And at least Herostratus didn't kill anyone - unlike Alexander the Great, who was born the day the temple burned and was clearly driven by similar motives, at least to judge by the number of cities he named after himself.