Wouldn't it have been much more sensible to have a lowercase version of alphanumerics in the QR code standard? Almost all URLs are lowercase, and even if the have capitalised parts, in most cases they're case-insensitive.
QR codes were created for labelling automotive parts, not for URLs. Part numbers are usually uppercase alphanumeric, with a few punctuation characters.
QR codes existed for over a decade before smartphones brought them into the mainstream. They're high density replacements for barcodes, which are uppercase by convention (or in some cases like Code 39, only support uppercase). URLs in QR codes are a later innovation.
