Case sensitivity is actually a powerful feature of Unix systems as it allows for multiple valid string variants of a single word. For example, common Unix conv

Case sensitivity is actually a powerful feature of Unix systems as it allows for multiple valid string variants of a single word. For example, common Unix convention in the 1980s-1990s was to name user-created directories with a capital to make them easier to see in a regular directory listing without color (e.g. Poems is a directory, while poems is just a file). I've used it heavily with content revision (e.g. CATHENA02.yaml is the second cathena configuration file in testing while cathena02.yaml is the production version of it). Plus, making a filename case-insensitive for processing purposes in a scripting language is very easy. Consequently, I can't imagine a reason why I'd use case-insensitivity in ext4.