From my perspective, you would be using Monero as a means of transacting, converting it from Bitcoin as needed. I really don't see why the two can't coexist since Bitcoin obviously isn't fulfilling some of the things I believe it should be.

Privacy coins not existing at all wouldn't be a good thing (to me) if the same doesn't exist on Bitcoin. 

 This is precisely the use of Monero that I have analyzed, but it is neither economical nor practical, so I am not convinced by it or any of the other methods I have mentioned.