Defaulting to "no" would be better, but I can't fully agree with you in the "innocent" part because the real problem are users that can't use a computer, and this is just a tiny annoyance compared to other things that can happen if the user "can't read" and clicks next, next, next without thinking.
I would rather say that this kind of behaviour is one of the tiny little things that make computers harder to use in general.
We all know of relatives that just use their computer for Facebook and Farmville, and get "infected" by a needless virus scanner and/or alternative browser every time they have to update Flashplayer.
It is so vicious that even people that are aware of this kind of practice may get caught. The fact that users "can't read" (but equally often programmers also "can't write") is no excuse.
It doesn't only affect users who don't know better. I can't tell you the number of times I've hurried through an installer only to realize I forgot to pay closer attention and uncheck a checkbox.
If I download a program and install it then that's my intention. I don't intend to install other software along side of it.
Just saying, this isn't an issue about people not knowing how to use a computer. It's a dark pattern that hurts everyone.
This was posted to HN recently, and it sums it up nicely: http://coding2learn.org/blog/2013/07/29/kids-cant-use-comput...