I was recently rereading Ivar Jacobson's book "Object-Oriented Software Engineering" which is considered a seminal work on OOAD, OOSE and OOP. I came across a statement in which he writes "objects should not directly manipulate the properties of other objects". Later, in context, he is shown to mean that this applies to both reading and writing properties.

Microsoft's COM theory more-or-less says the same thing: objects expose interfaces but not properties.

So....are we reversing central tenets of COM and OOP by using Access and Assign to intercept property calls/puts when there shouldn't be any direct manipulation at all?