While I do mostly agree with you, and think that there's generally no need to bathe on mostly-sedentary days in a mild climate, there is certainly an actual answer to your maybe-hypothetical question: "... I will never put my self in a position where anyone can smell my body odour but why shower so frequently if your body isn't telling you, "it's a bit dirty over here, I could do with a rinse?".

I can certainly attest that I've known lots of people who seem to be unaware that anyone can smell their body odour, and presumably can't smell it themselves. The keenness of the sense of smell seems to vary a lot more among people than other senses (except perhaps sight, but we use technology to normalize that).

So having known many people who are unaware that they smell, I certainly worry the same could be true of me - I have a decent sense of smell, but probably there are many people who would notice my body odor before I did.