This naive assumption on the competence and benevolence of companies falls down when one has experience with the software industry, especially the professional one, where many companies are known for horrible release practices, disrespect for their users, complacence, money-milking, etc.
Steinberg, especially in early 00’s, was notorious for leaving known bugs unclosed for years on end, and then coming up with a new paid version to fix them (not unlike finally getting Retina support in another 8.5 or 9 paid release, 5 years after the feature has been introduced).
Not to mention companies like Quark and other such bad apples – with them the treatment of customers and releases was so bad that they managed to lose their #1 leading position in their industry, and most of their users, in just a few years.
I think that Steinberg is better post-Yamaha in those regards, but still this lack of transparency (and results) nearly 2 months after the GM is troubling.
For people who don’t have other needs to update to El Capitan of course it’s OK, they can always use older versions, especially if they only work in music.
Until then, this of course makes anybody buying a new macbook/iMac --that comes with El Capitan – to use it with Cubase to have to manually reinstall a previous version of the OS on it, perhaps one without the latest drivers for the screen and peripherals too.