People, stop advocating random operating systems saying "they're secure" or implying that they're more secure than others. As some here have said already, they're only as secure as well as they are maintained, by their developers and well as their sysadmins.
Some operating systems have had a worse track record when taking in the number of root-level compromises into account.
But, just like when Code Red "sorted the men from the boys" in terms of Windows sysadmins, those with half a brain configured their servers properly, avoiding the obvious potential risk, from those that didn't, who ended up spending a long time cleaning up their systems or reinstalling them.