Like it or not, Gator and friends DO present EULA dialog boxes and such; that blue, underlined text in the "Security Warning" box takes you to the EULA for Gator and the time thingy, for example.
This shit doesn't "accidentally" install itself; you DO click "OK" at some point.
Of course, if you'd like to propose a concrete example of silently self-installing spy/adware, be my guest.