First, we're talking about *apps* not browsers.
Second, people might dislike adverts, but most people would rather put up with them than pay hard cash for apps. That's true of the wider internet, and historically has been true of ad-funded free-to-air TV and ad-funded free papers and magazines. It's not the producers who dictate this but the consumers. Without ads there's less content and the budgets of the content there is, will be smaller.
Of course the joy of such as system is some of us can be free riders -- blocking and fast-forwarding through ads, while still getting the free content. So long may it reign. But I freely admit I'd part of the problem and try not to bitch too much.