Why doesn't C# have package private?

I'm learning C# and coming from a Java world, I was a little confused to see that C# doesn't have a "package private". Most comments I've seen regarding this amount to "You cannot do it; the language wasn't designed this way". I also saw some workarounds that involve internal and partial along with comments that said these workarounds go against the language's design.

Why was C# designed this way? Also, how would I do something like the following: I have a Product class and a ProductInstance class. The only way I want a ProductInstance to be created is via a factory method in the Product class. In Java, I would put ProductInstance in the same package as Product, but make its constructor package private so that only Product would have access to it. This way, anyone who wants to create a ProductInstance can only do so via the factory method in the Product class. How would I accomplish the same thing in C#?