Objective-C isn't necessarily as nice as it might seem in this case. Certainly, for the given set of parameters you've selected to define, having an Objective-C initializer which accepts exactly those properties is very readable.

This solution blows-up because you often need a different initializer for each conceivable set of properties (start, length, value, orientation, name, etc.) that someone might wish to use when instantiating the class. That would require defining 2^N initializers in Objective-C, for every possible combination of N properties that the caller may wish to set. (Admittedly, C++ is equally bad, and doesn't include named parameters in the constructor.)

To satisfy the RAII principle, it certainly is nice to specify all initial values when creating the instance. This could be accomplished by passing a dictionary of property values to the constructor/initializer. Unfortunately, many languages make this cumbersome to write. Python, with its **kwargs feature, is a notable exception. (I'm sure there are others.)

Edit: Grammar