You could click one button to convert a color image to black and white, but it will look like "mud." Yes, that is the official photography term for it :) If you've ever seen a black and white photo online or printed that looks really flat, or like "mud", you will know that there was no correct conversion done.
Here is an example:
Looks great in color, right?
Click of a button conversion. Kinda looks like mud. I want to see my subjects pop more off the background, and I want to see more detail in the highlight areas.
Adjusted for Light to Mid Tones, so you can see detail in the waves and clouds, but now my darks are too dark.
Adjusted for Mid to Dark Tones so that the darks are not too dark, but I've lost detail in the waves and the pier is now too light.
Final edit compared to 'mud'. Combining the light and dark tones for the exposure I want. I now have good contrast without losing definition in the waves or pier.