Are you sure you didn't just go ahead and basically make up these people who don't want money to touch their book because it's dirty?

No. I've seen such people. When I look at the mirror, for example. Notice that the standard was explicitly set to:

not the actual reason (even in some small part)

The observation that this kind of absurd claim is positively received and even supported by similarly ridiculous petty sniping is disheartening.

I've known at least a couple people who found it yucky to handle cash right before a meal for that same reason.