If your light level did not matter, then I would agree, but customizing your armor while keeping your light level is a totally different story. Before the DLC you could only get to 30 by having 4 raid pieces or 1 exotic + 3 raid pieces. To get to level 32 in the TDB you must have the same set up but with the new raid gear. Does that sound 'Fully Customizable' to you ? And yes, it does matter if you want to play the end game content and do well (Iron Banner, Raid on Hard, upcoming Trials of Osiris). So yeah, if you don't care about your light level you are technically correct, but since most people care about their level you are wrong.