Whilst antiviruses exist, you only have to see the amount of infected users on some IRC networks to see how many people do not benefit from them. Not everyone is computer savvy. Not everyone knows about backdoors and viruses and what to look out for. Some of the top scripting websites don't accept .exe files with scripts either.
Given the amount of backdoored/infected scripts that actually become popular (despite savvy user's best efforts to warn people) I have to agree this would be disastrous.
Regards,
