Brian, I usually agree with you, but my partner and I have shared the same Apple ID forever and we each get calls and texts separately. I call him, his phone rings and he answers. He calls me, my phone rings and I answer. I don't get his texts or Facetime calls. He doesn't get mine.
I understand many don't believe in sharing an Apple ID, but it's not always wrong to do so and for us, it works quite nicely.