Is this an Apex bug, documented limitation, or am I just crazy to think that the following should be possible?

Here is a simple example demonstrating an example of attempting to call an overridden implementation of a protected method from a superclass. I've set the example as three separate class files:

Parent Class:

public virtual class TestParent {
	  private string data = 'Parent Data';
	
	  protected virtual string getData() {
	    return this.data;
	  }
	
	  public string getText()
	  { // This is where the Overwritten child method gets called!
	    return 'Data : ' + this.getData();
	  }
}

Child Class:

public class TestChild extends TestParent {
	private string myData = 'Child Data';

	protected override string getData() {
		return super.getData() + ' and ' + myData;
	}
}

 Test Class:

@isTest
private class inheritancetest {
	static testmethod void testUseChild()
	{
		try {
			TestChild c = new TestChild();
			c.getText();
		} catch (Exception e) {
			System.Assert( false, 'Exception! ' + e.getMessage() );
		}
	}
	
	static testmethod void testUseParent()
	{
		try {
			TestParent p = new TestChild();
			p.getText();
		} catch (Exception e) {
			System.Assert( false, 'Exception! ' + e.getMessage() );
		}
	}
}

I was expecting the test methods to pass without any issues, instead they fail because "[TestChild].getData() is not accessible", (a line number indicating Test.Parent.getText()'s code statement is provided).