Another recent study proved that angioplasty, the procedure in which stents are used, did not help patients when used to openan artery days after a heart attack occurred.
If the millions of internet-connected Macs are left open to attack then this increases the chance that an effective Trojan or piece of spyware will reach critical mass and spread rapidly, and it also increases the incentive for a bright programmer to write Mac-specific malware that could affect me.