Unticking a box might seem like a small thing, but consider the following:

• The number of Flash Player and Java updates are frequent due to security issues and staying up to date is very important.
• Updating Java or the Flash Player is anything but a frictionless process as it is. For Flash, upon clicking the update prompt I am taken to a download page, where I must untick the box for whatever crapware is on offer, click download, open downloads, launch the download, close web browsers (and possibly other applications), click retry, finish. Java is a little better, but not much.
• Many people have multiple devices to update which magnifies the annoyance factor.

We are not in the 90s any more. Apple, Microsoft and Google have all managed to make updates a 1 touch process (or less), and this is the expectation of your users.

So stop being precious about distribution, but in the very least, stop abusing the update process as a marketing opportunity. It is irresponsible and annoying to millions of people every day.