You're not "leaving them"; making the ROI for an ad 30% lower (given a 30% Chrome install-base) is usually enough to make the advertiser give up on that ad, because they could instead be running an ad that converts ~90% as well and not losing 30% of their impressions in the process.
Now, the advertisers who only run these mal-ads will stick around and continue running them. They're also the ones who would fight tooth-and-nail to make their mal-ads more clever, instead of giving up and switching to regular ads; so they're exactly the ones Google will have a hard time discouraging at the ad-network level.
My hope for those is that other browsers simply copy Google's strategy here. If Chrome, Firefox, and IE all do this, there's pretty much no point in running these ads any more.
Now, the advertisers who only run these mal-ads will stick around and continue running them. They're also the ones who would fight tooth-and-nail to make their mal-ads more clever, instead of giving up and switching to regular ads; so they're exactly the ones Google will have a hard time discouraging at the ad-network level.
My hope for those is that other browsers simply copy Google's strategy here. If Chrome, Firefox, and IE all do this, there's pretty much no point in running these ads any more.