Your point (c) is the most important, in my opinion. I work in computing theory research at a major UK university, and well over 50% of the desktops I see used are Macs, and about 80% of the laptops. Many of our undergraduates also use Macs. A working Java implementation is quite important for this area - both for Apple, to ensure we keep buying them and Oracle, to stop people just saying "Well, we don't use that much Java anymore, let's just drop it".