Wrath sucked and it was the start of a lot of systems. I actually stopped playing towards the end of Wrath for the next two expansions because of dumb shit like LFD making me sit in town and doing nothing but queuing while at the same time every raid was made pointless by the next so you had no reason to raid Ulduar when TOC came out that sucked.
Also, Strands and Wintergrasp (which I forgot about) came out in Wrath and both sucked. Conquest or whatever it's called came out in Cataclysm I think, and Cata was a shit pile in its own way.