The vast majority of people are not deliberately choosing to install the software. They are "accepting" it by accident, by pressing the wrong button or because they are rushing through the installation and are not paying attention.
No consumer wants this stuff. The advertiser's software is a nuisance and gives no advantages to the end-user.
That's one of the hard things about advertising-- beyond an informative product announcement, most other advertising ranges from useless to annoying to the consumer. I know that I spend a certain amount of almost unconscious mental energy ignoring advertising, and any time I do research I have to sieve the results to filter out biased advertising-driven material. (It's particularly bad in health-related stuff.)