He's also engaging in the fallacy of believing his personal experience is parity with most users. His personal experience doesn't answer the question he asked (the first line) any more than mine does. (I boot at least daily.)
Even if he's right about what most users do, he still has to establish that ignoring the minority is the right thing to do. Linux operating systems have an extensive history of being good for the long tail. We owe much of its success to it.
Also, if booting is not important because of its frequency then it stands to reason that installation (Anaconda) is not important for the same reason, right? How often do people install Fedora anyway? Certainly less often than they boot.
At any rate, unless one thinks that Anaconda's shortcomings were really the result of it being developer starved, there's no reason to wave the "Priorities Now!" flag (even if developers were a generic blanket resource that could allocated willy nilly).