It's worse than that, actually. Experienced computer users interact with a computer in a completely different way from inexperienced ones; at some point, experienced users develop the ability to do some kind of fast cognitive relevance filter on the screen, so they know which UI elements they can interact with, which ones might be important, which ones aren't, and so on.
Less experienced users can't do that -- they have to read every single word on the screen and make a decision about it. They mitigate this by memorizing specific actions. i.e., "to send an email, first I click in this area, then I click on the blue thing, then I click in that area..." (which is why constantly changing UI is such a problem for them, btw).
So what do they do with installers like this one? They just click "Next" with all the defaults on. The text on a screen like this is no different to them than the text of the EULA that none of us read.