People buy permits and make donations to CODE. and it’s how it is financed. It’s a player-made problem - or let’s say for some it’s a problem and for others it’s not.
Just the other day was another kill report posted on a freighter gank. You can read about it here. The part, which matters is the player had a permit from CODE. and got ganked by others.
For a psychological study on the phenomenon read here. 
Ganking someone’s ship just because it’s expensive is EVE’s version of a “sack whack” or “wedgies”.