2 reasons: First, it is not my original pattern. I ran across it online somewhere, and this was how it was tied. I just can't remember where, or who tied it. I also cannot find it again.
And secondly, I didn't think of it at the time. Those are great ideas for improvements, and I will be incorporating them into the future ties of this pattern.
I wonder if those improvements would qualify it as a new pattern? You may have invented a new fly.
Good job.