Ads cost too much? Not, 'let's stop advertising on iOS', instead, Let's give up.
I can understand as much as the next iOS developer that changes that require large workarounds due to software/hardware updates that aren't backwards compatible are a pain. But as a developer, you suck it up, modify your content, and continue (Edit: Of course, if it makes financial sense, positive ROI, etc, to keep selling on the Appstore).
Why do developers feel entitled to hardware devices that will always work with legacy code? Apple makes changes that try to push their technology forward to the latest and greatest, all the while removing legacy cruft at the expense of sometimes trading off backwards compatibility. It makes sense that they expect their developers to keep up with the latest trends and produce content that's formatted to the current specs, not simply relying on old tech specs.