Yeah. I guess you can analyse it as:

1. Denying the antecedent: “showering every day prevents smelling bad, therefore if you don’t shower every day, you will smell bad”
2. Confirmation & Selection bias: “that person smells bad, therefore they can’t shower every day, making them an example of not showering every day leading to smelling bad”
3. Bias of anecdotal evidence, presumably - at least, I’m assuming that most such people really do smell bad to themselves after only a day, which is treated as a reliable indicator of everyone’s condition.

It’s quite interesting to me, because it clearly becomes a very emotive topic when the difference between waiting one, two or three days to bathe is pretty abstract. I have developed a hypothesis that it’s the feeling of having a shower when one is feeling sticky and sweaty and dirty, and then coming out feeling nice and clean, that gets readily associated with bad odour. I then think that this link simply can’t form easily if your feeling when coming out of the shower is not “nice and clean” but “disgusting ball of skin-flakes held together only by paraffin and artificial grease”.

I have encountered this kind of attitude before but I was actually surprised to find it that prevalent here, because I expected more people to be sympathetic to conditions which require deviation from the norm.