I think some of it just that different people have different priorities. Some of what protected Apple was vanity. I think Steven Jobs cared about how people saw him and his products. He wanted to be the guy who made a premium product that he thought was cool and was proud of. The longer time went on, the less Apple execs cared about what he would have wanted and started caring more about what they wanted.

I also think that they're counting on people to have been conditioned to accept ads everywhere. Microsoft has been infesting their OS with ads for over a decade which, like it or not, has normalized that practice.

Apple is counting on the fact that iphone users aren't going to switch to android devices just because the company starts pushing ads in their face. In addition to all the customers who don't stop buying apple products because they are filled with ads, a percentage of them will start paying for more Apple products and services because of the ads. The obvious next step from here is to increase the amount of ads until that's no longer the case. Get used to seeing ads iphone users; it's only going to get worse.