Can you elaborate on that experience? I would have thought users not typing filenames wouldn't care less, and that users who are typing filenames would tend to be developers or 'advanced' users who aren't confused by case-sensitivity, and recognise the advantages.
That's how I see it too - inexperienced users will only be typing in filenames to name new files and likely use a GUI filechooser for selecting existing ones, while the ones typing in filenames are probably using CLIs.
The common complaint "but it's annoying to have to type in the filenames exactly" can be solved with tab-completion (I'm surprised how many CLI users don't know their shell has this feature), and using sane naming conventions like not GiVinG yOuR fIleS_stUpiD-NaMESLikEth1s.
