Their window of opportunity to hack centralized exchanges is likely closing - it should close eventually - and they must be looking toward the time when their attacks will have to be along another vector.
That's an optimistic viewpoint!
Unfortunately, centralized providers are here to stay until there is some very clever on/off ramp to claim fiat.
As for your main point, about the hackers...sure, there are always nefarious sources at work. But there are probably far more hackers gathering meta data on identities with your information from the major banks and major credit cards, which all have experienced major leaks recently.
The most serious security problem right now is ransomware.