What I do in my home directory is also Apple's policy, and the leading caps is applied also in system folders and not only in individual users' folders. This is usually not the case in Linux where the use of lowercase letters only is applied pretty much everywhere (at least last time I checked). Thus, creating a home directory using lowercase only does not make sense when virtual every other folder in Mac (at least the ones the normal user sees) are using leading caps.
I was expecting Apple to suggest by default the name with leading cap, and with no spaces - especially since it is not trivial to change it later. Since they did not do that, I suspected there is some code somewhere which may rely on this - but you seem to reassure me it does not have any functional use.
I have been using a Mac for ~8 years now and always used a leading cap for the short name - never had any issue with it, but I still was not sure if this could lead to trouble in the future.
In the related support document (Change the account name and home directory name on your Mac - Apple Support), Apple states specifically: "When modifying the account name (short name) or the home folder name, the name you use should not contain any spaces." This is understandable for the reasons you have mentioned. But I also read in some forum that in the past Apple specifically stated the short username must use lowercase - so either this statement was wrong, or Apple realised there is no need for such a demand.
BTW, the colouring in terminal is familiar (I use it myself), but do not answer my question, and I don't know of anyone using caps and small letters to distinguish between directories and other file types.
