When you get a pet you are making a commitment to keeping it healthy. The bottom line is that this snake is NOT IN THE WILD it is in your home, under YOUR care. In the beginning, it was not showing pain as a defense mechanism to not show fear and look weak. The reason now that your snake isn't showing any reaction to you poking his hemipene is likely because the tissue has become necrotic and probably can't feel you poking it anyway. Infection will set in any day now and the snake will die from a lack of vet care, that YOU were supposed to provide.
Why would you take a child to the doctor if it were sick? Because you bore the child and have a responsibility to take care and nurture it.
Why would you take a snake to the vet if it were sick? Because you took it under your roof under the guise of a caring pet owner and have a responsibility to care and nurture it.