While it is true that windows is so ubiquitous that virus writers tend to target it, the amount of infected windows computers are probably the same percentage as apple has market share. Newer versions of Windows, like 7 - the greatest OS mankind ever built, comes with some level of built in protection so even your average apple-minded user will not easily get it infected.
Back to the topic at hand - Apple made dodgy displays - people complained and apple turned a blind eye. Lets take this in the PC world.
Samsung/Philips makes a bad display - people complain about it and get a LG/Acer/Sony instead. Samsung/Philips now needs to make up for the booboo.
Or with denial :
Seagate makes a batch of drives with a firmware bug that renders the drive unbootable in some cases. They keep on denying it - people buy WD/Samsung hard-drive and Seagate is forced to admit the problem and release a fix for it. They habe a bad reputation that will take years to recover from.
See, that is the power of choice and companies needing to be on their best behavior to win buyers.