Such a button would make it easier for people to go straight to their Netflix account, rather than clicking through other menus, which take time and could potentially distract the viewer.
This reminds me of the "icon on the screen" or "icon in the system tray" discussions people used to have in an earlier wave of online media, about 2000, when it was assumed the display would be a PC, and therefore the value of on-screen real estate was deemed valuable.
It isn't a trivial advantage, as icons on main smartphone screens are seen as having value, or as preloaded software typically is seen as having business value.
Netflix Button Coming to Remote Controls (Wall Street Journal subscription required)
