Menu option "Select startup disk on desktop" greyed out when Finder window is active
I created a workaround using KeyboardMaestro: only in Finder, on hotkey (⌘⇧↑), execute AppleScript:

tell application "Finder"
    select window of desktop
    set selection to item 1 of desktop
end tell


Weirdly enough it doesn't show that it is selected, but Cmd-down opens its window.