Actually Warren9, its not that simple. Firstly, you have to tell both approach and tower that you will not be able to accept visual circuit in the event of the missed, so as you say; the "published missed approach is always available", is not correct. You have to accept the circuit if you have not told both these controllers you will not accept it.
Also, I have not heard controllers state the phrase "in the event of a missed app, will you accept the visual circuit?", in the last 12 months. I presume it has been removed from their manual.
I agree with you philosophy on MAP alt in MCP.
Our SOPs state to set the circuit alt for MAP alt if wx conditions suitable.
So seems not so cut and dried as I would have thought.