Well, I guess if you want your computer to be truly protected then you're right... I'm arguing that you don't need your computer to be fully protected. Use torrents for your downloading, only get ones that are given the OK by other users and check the files before you download... it's not hard to avoid viruses. In fact it's mind-numbingly easy. Even my relatively computer illiterate family has no issues sans virus protection. Don't go to sketchy sites. Don't download and install shit unless you know what it is and who it's from. That simple.
Viruses are constantly updated so even with software you aren't protected at all times, so it's better to just... you know, not be a dumbass. Spyware and shit is impossible to avoid but easy to remove with a couple programs that don't need to be running constantly like Spybot S&D. I donno man, I'm on my computer way too much, and if I'm on it I'm downloading shit. If I'm not on it I'm usually downloading shit too. Never had a problem. Ever. Seems like a waste to me.