But some people lost a LOT of money here. Why aren't they pursuing it legally?
Probably because, nobody lost any real value, or big amounts. I mean, we all have coins in there, but not billions of euros, more like a few dollars each.
We are all in there with small amounts, personally i'm also in just about the numbers you are in
and i believe most users have about same numbers, with exceptions of course..
Also, i dont really think that anyone actually trading coins does leave large amounts in exchanges, and people did have time to withdraw most alts before site went down..
At todays rates, if one has say 5 btc in there, they are really worth less than organising an overseas law suit.
Its not like one pays 150 euros to a lawyer and you instantly get your coins back, it would take a lot of resources.