MACS were safer because Windows dominated and relatively few miscreants in Pakistan or the Ukraine wasted their time writing malware for them.
Recent technological developments have changed this.
Looks like it finally caught up to the Macs...as I knew it would.
While this is part of the reason, you are ignoring a fundamental difference in the approach to security and design. Windows uses a completely different and frankly weaker security model/design, especially in older versions of their OS than UNIX (which OSX is based upon).
Any computer can be hacked, but when you have a security model that is more flawed on computer a than computer b, computer A is going to get hacked more.
No computer is hack proof, it its on the internet its at risk, period.