Yes, there were major dumbdowns.
Prime examples but by far not the only ones is the suppression of DOT snapshotting, the suppression of many subtleties such as when to best use CDs/procs, mostly no more mana/resource management.
In PVP also the game has become much less interesting and it is harder and harder to differentiate between an outstanding and a good player. I'll let you watch Cdew's stream or other world-class PVPers that can go into much more details than I.