Not only do people install it, I see it required in corporate IT all the time. As in, they even set a VPN policy that checks your anti-virus definitions for currency and will refuse to connect if the definitions aren't current or if anti-virus is not installed. These same corporate IT who force 90 day password changes, and nonsense like 5pEAzhawh$ instead of fivepizzassoundsgoodbutdontforgetthebeer because no matter what longer is better.