I really don't want to be negative, but every browser update in the past year feels like a step back. This is true for Chrome and Firefox. Each update contains more "Sign in to your browser" stuff plastered everywhere. Eye candy is added. Useful configuration options are removed.[1] Many of these changes seem to be made with the goal of increasing revenue, not improving user experience.

Rule #0 of business is: Listen to your users. For browsers, one straightforward way to do this is to look at what extensions and addons users install. By far, the winner is adblock. Almost everyone who knows how to block ads does so. Therefore, if you are making a browser and you care about user experience above everything else, you will have ad blocking by default. That no major browser does tells us what their priorities really are.

Again, apologies for the negativity. This has frustrated me for some time.

Edit: I realize that if everyone suddenly started blocking ads, there would be darkness and chaos. But the current situation is only tenable because a small fraction of users have the know-how to get what they want. You can avoid ads if you are technically proficient or know someone who is. Everyone else has to put up with ads. Advertisers annoy millions if not billions of people, effectively subsidizing the usage of those with ad blockers. That doesn't seem fair to me.

1. Such as the old new tab page in Chrome: https://code.google.com/p/chromium/issues/detail?id=326788