This is a list of words that have several unrelated meanings, where one of the meanings happens to traditionally have different casing than the others. These are two different issues that happen to coincide, neither of which implies that the English language itself is case sensitive.
Just because you've gotten used to something, does not mean that that is a good state of affairs. One of Unix' biggest HCI shortcomings is its case sensitivity. I'll also note that Mac OS X has wisely removed this limitation.