Their goals are not really anti-competitive. The point of this feature is to stop the bleed from ad blocking extensions and alternative browsers which are the real threat to their business.
But there is no way for them to do this that doesn't end up looking really bad.
Probably they know it will get shut down eventually, but it will take years to happen, so worth it.
1) Users say they block ads because they are annoying, rather than any deeper philosophical arguments about the nature of advertising
2) Users tend not to bother with white-listing and just use the defaults - i.e. block all ads, even Google!
3) Once they have used an ad-blocker, users are very resistant to browsing the web without one
4) Users who ad-block are among the most educated and tech-savvy, and as such are a valuable demographic to miss out on
5) Ad-block use is growing steadily with no signs of slowing
So, Google's provocative and somewhat desperate move is an attempt to gain control of ad-blocking before it becomes a serious threat to their business, even in the face of serious backlash. I hope they fail.
That's true villainy right there, how dare they! /s
1) As you pointed out - Users (or their friends) will go out of their way to install an ad-blocker and set it up the first time.
2) If I still find prominently placed Google ads annoying (and I do, despite the fact that they're not animated or audible), then I will still go out of my way to block them.
One could make the argument that by putting a web browser in Windows, Microsoft was only providing a common service to their default OS. The problem here is that Google makes almost all its revenue from the very medium that they are now actively blocking from other providers.
That doesn't change the anticompetitive nature of their behavior but it does explain the motivation.
This is using large scale marketshare in one market to effect a tangible and monetary benefit in another market.