You are mistaken, the official rulebook is published and it's right there in the blurb that you agree to during sign up.
It's really short, too, as there is only one rule: Apple decides whether an app is accepted and they will neither tell you the criteria nor the reasons for a rejection.
If you don't agree with that then you should not tick that checkbox. Easy, huh?
I find that hard to believe. I think a rulebook does exist, but that they avoid publishing it because they want to have the 'final say' even if somebody would play within the rules as specified in the book.
And that makes sense, because it would open apple up to being sued for breach of contract, and that is exactly what this whole thing is about. A one-sided contract is no contract, consideration is to be given to both parties. Developing an application is an investment and you should be allowed to inspect the full terms of the contract under which you make your investment.
Excuse me? I said nothing like that.
Yes, they probably have an internal rulebook but that's completely irrelevant because they chose to not disclose it. They are free to make that choice, just like you are free to not do business with them on these terms. It's called "Free Market", wikipedia can tell you more.
A one-sided contract is no contract, consideration is to be given to both parties
I'm starting to think you have serious reading comprehension problems. The contract is not one-sided. You get to read it and you must agree to it.
Developing an application is an investment and you should be allowed to inspect the full terms of the contract under which you make your investment.
You are not only allowed to inspect the full terms, you are required to inspect and agree to the full terms.
The full terms are: Apple may or may not accept your application and they are not obliged to tell you any reasons for their decision.
If you think apple "should" be operating differently then don't do business with them.
You seem to think there is some sort of godgiven right to get into the App store. There is not. It is Apple's personal playground. If they choose to accept apps only on mondays then they are free to do so. If they choose to reject apps because they would compete with their own products then they are free to do so. If they choose to reject apps without even telling you the reason then they are free to do so.
They have this freedom because you, the developer, checked that little "I agree"-checkbox, remember?
A transparent approval process would solve this instantly.
And even Apple would benefit.