Why does a custom android view not take a TypedArray as a argument

Question

I am learning to write custom view in Android, and reading the documentation.

A custom view is passed an AttributeSet as a parameter. But the documentation says to get a TypedArray using the following code

TypedArray a = context.getTheme().obtainStyledAttributes(
        attrs,
        R.styleable.PieChart,
        0, 0);

So why doesn't it just pass a TypedArray to begin with? When would you want to inspect the AttributeSet instead?

The documentation specifies that you do not want to inspect the raw AttributeSet because...

-Resource references within attribute values are not resolved

Wha?? Does this mean if I have a custom attribute x=10 in xml, that it will not equal 10 until it is resolved?

-Styles are not applied

If I have a custom attribute in xml x=10, what would applying a style do it actually do?