https://www.youtube.com/watch?v=iSgA_nK_w3A
This was shared to me in discord some time ago, when we were discussing the 4.0 changes. While this is about Street Fighter, many of the points here can very much apply to FFXIV's PvP, and the significant changes from 3.x to 4.0. It's a bit long at 14 minutes, but it's well worth a watch to become more familiar with why the old PvP community is so upset by the changes.