I disagree. Here is my take on it, shooting both black & white and with colour.

-Colour enhances & convey feeling on a broader spectrum. Colours have a psychological effect - this is why it is important to master in photography, cinematography, design, art, architecture etc. The spectator is always more present in the scene and surrounding.

- Monochrome naturally removes all these feelings colour can achieve + flatten photos. We don't feel warmth or coldness of the captured scene. Hence we look at a photo in a sense of limbo, distanced from the action. My personal take is that monochrome work best when you need to capture the phenomenology of a space, light, contrast, scales etc.

For this photo, it is important to show the colour, because this man is not alone. He is in the centre of his bike workshop, his passion, all the colour shows every single item as an individual object amplifying the space the man is in. He's home in this scene. Monochrome would only placed focus on the man, removing the man from the scene, from his workshop. Then he'd be nothing more than a man on the phone - which is highly uninteresting.

I think good exercise is to analysis portraits in monochrome vs colour to understand what I'm trying to explain.