Say what? The amount of money Apple makes from apps is a drop in the bucket compared to their overall profits. They've sold $10 billion worth of apps in all the time they've been selling them, which gives Apple $3 billion from its 30% cut. They make more than that from the first month's sales of a new model of iPhone.
Could Apple do more to hamstring the bad actors developing games targeted at getting kids to spend money on useless in-app "stuff" like smurfberries? Sure, but if they do it too much, those game developers will just flee to Android, since Google doesn't have any sort of walled garden the games developers will be free to pull their underhanded tricks there. Before you say "parental controls", these exist on iOS too, the problem is parents don't know how to secure their devices until its too late.
Now that Android tablets are outselling iPads, there will be more of these types of games coming to Android since parents buying a tablet for a small child are probably going to want to buy one for $150 instead of $450, knowing that it has a higher than average likelihood of being broken when its left in the hands of an 8 year old.
Google takes the same 30% cut Apple does, when the reports of kids spending $1000 of their parents money on berries on an Android tablet start coming out, will you make the same claims about Google you did for Apple? The amount Google makes from its 30% cut is of course a similarly trivial percentage of Google's overall profit.