This is indeed true. But the thing is, there are virtually no viruses, in the traditional sense, anymore. Not sure there have been in some time. So we finally have learned a thing or two. Now what we face mostly is malware, which are a different type of exploit. Viruses required one to activate them by clicking on an executable file. The reason it is uncommon for Macs is because the dot exe files (executables) would not run on one. Executables are Windows OS native. So it wasn’t until Apple decided to go with the Intel chip which allowed Mac users to boot into a Microsoft emulated environment where one could open an executable and have it be able to do it’s thing, that it even became possible for Mac users to be vulnerable for such exploits. And even then you would have to know exactly what you were doing as it takes some time to re-boot into another OS partition.
Some said that since most people used an MS configuration computer there was no reason to make exploits for an operating system only 6% of users ran. Other’s said that the problem was that these ‘script kiddies’ (as they were known) had virtually no knowledge of how to write a virus for the Mac as Apple used to keep it’s source codes under wraps. Even the excellent Apple team at Microsoft would take ages to sort things for their Mac versions of Office. But in the end, they were even better than their MS originals. Either way, when Apple decided to base it’s OS kernel on Unix, it became much harder system to infiltrate. But when the company switched to the faster Intel chips, it made way for a trade-off: it added speed and the ability to successfully run a Windows environment on a Mac. But in doing so, knowingly, Apple sacrificed some safety for speed at the price of added vulnerability.
But the thing now is there are, and have been, a lot of anti-virus manufacturer’s (Kapersky, Sopphos, McAfee, et cetera) dying to make their applications a must for Mac users since the numbers are now beginning to favour a format which is known invulnerable to traditional viruses. And now they are really wanting that revenue. For years McAfee has claimed to have created Mac viruses and would publicly speculate how dangerous they would be if they were ‘in the wild’, a term used to mean, in their labs but not in the general public, to try and spook Apple (and especially Mac users) into toeing the line and buying anti-virus programmes.
Another example is about six years ago Apple decided to stop supplying their new Macs with Adobe Flash, as it was the new chosen platform of hackers for creating exploits on the web. This infuriated Adobe so much that they tried for years to sue Apple for dropping their product, without success. Currently Java exploits are the most common and so Macs have the option to switch that off whilst surfing the web but with the knowledge that not all website will work as they should without it. So again, there is a trade off. But other than trojans, which can be picked up by anyone on any system (although not always guaranteed to do their dirty work) there have simply been no viruses that the Mac is susceptible to since the introduction of the Unix based OSX in 1999/2000.
I would like to note that this may not be completely technically correct as this matter has never been an issue for me and am just trying to make a point. If anyone would like to point out any factual inaccuracies, I would welcome the corrections.