So if my email is [email protected] because I want to be cute people will have to try 6 times before they finally get the right email address? Imagine telling that to someone in person. This kind "weird" casing isn't that rare and doesn't require cute usernames: "[email protected]", "[email protected]", "[email protected]", etc.
Languages that don't have case is not an issue; the situations where a lowercase <-> uppercase mapping is not simple are actually not that many. It's not trivial, but not all that complex either. The most annoying part is Turkish, Azeri, and Lithuanian where the rules differ a bit but the used language is often unknown. For the purpose of matching things ("is this email address known in our system?") it's actually not that hard, since you can just treat several characters as identical (displaying text correctly to users is harder, but that's not important here).
I see this attitude in various situations, often under "falsehoods programmers believe" articles, which goes something like "it's hard in a few rare cases, therefore we should not do it at all for the >99% cases where it's simple and unproblematic".
Languages that don't have case is not an issue; the situations where a lowercase <-> uppercase mapping is not simple are actually not that many. It's not trivial, but not all that complex either. The most annoying part is Turkish, Azeri, and Lithuanian where the rules differ a bit but the used language is often unknown. For the purpose of matching things ("is this email address known in our system?") it's actually not that hard, since you can just treat several characters as identical (displaying text correctly to users is harder, but that's not important here).
I see this attitude in various situations, often under "falsehoods programmers believe" articles, which goes something like "it's hard in a few rare cases, therefore we should not do it at all for the >99% cases where it's simple and unproblematic".