I have a machines which I connect to that do not have any mouse connected. I have no problem in navigating systems with a keyboard and can run through installers probably quicker than most people with a mouse can, but when this dialog popped up for me, I was stumped for about 10 minutes. I employed every shortcut in my keyboard-shortcut arsenal and fell short.
I genuinely felt like this was not just some programming mistake (because the "Next" control was already highlighted waiting for me to hit Enter). It is a dark pattern that was purposefully introduced to their installer to make it impossible for users like me to opt-out of their installer.
A consequence of their deception was that they did get a dozen installs from me, but my dislike for Oracle increased tenfold, and in a quiet-protest, I'll make damned sure that I suggest any alternative to an Oracle product when I have reasonable alternatives (Without cutting off my nose to spite my face).