All the devs have said on the matter is that they don't want people to HAVE to use it, which is silly since the only time it would be compulsory from the community is when it's really needed (eg. BCoB or any other dungeon/ raid within the first week or two after it's launched). It's very difficult, or at least cumbersome to type all of the many instructions required to properly get people through Titan EX, Twintania, etc. and this would be seriously alleviated with in game voice chat. Not only that, people could stop relying so heavily on youtube if quick and easy communication was implemented in game. I feel like the developers are just saying they don't want players to feel like they have to have a headset (such items are cheap for PC and nearly all console gamers have them if they play online at all) so that they don't have to pay for the extra overhead of providing the service.