Personally I don't care about secure boot. Those times I used it, it only caused problems (tho never with Oracle Vbox) and if I can circumvent it so can any attacker that has physical access to my gear. Essentially I'm all for keeping our freedom and kicking secure boot....we need that customized kernel.
If I understand the link correctly, one will get bitten due to different keys when adding 3rd party changes/modules. That's much [security] ado about nothing IMHO but I suspect there are -Windows_dual_boot- users who will demand secure boot, whether they need it or not.
Like corporate EULAs and DRM: This isn't security it's user harassment, to make it quite clear that users aren't really worthy of the product, let alone to own or modify it. 
