Yoshi-P has stated several times that their design philosophy for XIV wasn't not to make just 'another MMO'. They want XIV to have its own feel and its own persona, and not be just another WoW clone. Some of their decisions to do this are better than others, and there are certain things that are obvious issues that need to be addressed... most of which they have stated they are addressing, but they have other priorities they want to deal with first.
They made crafting and gathering separate entities from the battle classes to give them their own 'life', as it were. Where crafting and gathering are things you can approach as your main objective rather than just something laid on top of the combat. It gives them a flexibility with the system to implement unique things that you wouldn't be able to do if they were just some sub-set of your character as a whole.
I kind of agree with the housing issue, I think they should have set aside a server to handle housing but it's also tied into the same issue as inventory space, where the server saves data twice as often as other MMOs and just adding more housing would only increase server load and impact stability. The whisper thing was specifically implemented to disallow RMT to whisper you while in duties since that would be a major distraction, especially since you can't blacklist them while in the duty (which is tied to the way the instance system actually works due to them being on a completely different server than your actual world).