Most of these "hacks" are inside jobs. They come up with excuses so they can easily run away with users' money. I've seen it time after time and it looks like this will never stop as long as there are greedy people in this world.
Maybe yes, and maybe not. Hackers are everywhere. Smarter, well yes also because they are so smart enough to know all accounts and steal. But exchanges must come to be smartest if and only if sites are well protected.