If you think my mother or sister have the faintest idea what a web browser is, or how one might be better than another, then you haven't met my mother or sister. To suggest that they made any kind of informed choice is absurd. They were influenced by marketing, plain and simple.
Personally, I'd be fascinated to see an in-depth study showing what percentage of web users chose their browser based on true/objective criteria, as opposed to marketing, brand preference, herd mentality, or wrong assumptions. Is exposing someone to marketing really what we mean by choice?
It's worth remembering that choice isn't necessarily the pure good we intuitively believe it to be. Western consumers have an extraordinary choice of food, yet that hasn't necessarily translated into healthier diets. This is especially problematic when the choices themselves are shaped by corporations whose interests aren't well aligned with the consumer's.