I think Jason Fried does a good job of explaining what's wrong with it in the post:
[...] at Basecamp we help people for all sorts of reasons. We apply credit to accounts for all sorts of reasons. We provide hardship exceptions for all sorts of reasons. We discount our software for teachers. We provide free versions for first responders. We extend trials for those who need more time. We extend payment terms occasionally for those who can’t make ends meet this month. We make exceptions because people are exceptional. We take enormous pride in helping people out. And we’re damn good at it.
If we had to push our customers through Apple’s system, we couldn’t do any of that. Apple’s rules prevent us from servicing our customers, yet Apple gives us no choice but to submit to those onerous rules or not be represented on their platform. [...]
This reflects my experience as well. If I can help customers with their billing issues, it makes my company look really good – we get an opportunity to provide exceptional customer service. If their subscriptions are managed via Apple, we don't really get that opportunity; instead, we're just one of many apps that can't make exceptions.
Apple is far less likely than the company that builds the app to care about the sorts of individual customer reasons for needing a trial extended, account credited, etc, that are mentioned in the article.
Yes, lots of companies are bad at customer service. But some are really good! (you can tell by how their customers gush about them.) And with forced in-app purchases, the good ones don't get the opportunity to do their best work.