I think there were a lot of frustrations surrounding RoS that sort of piled on top of each other that led to a general not so positive opinion of RoS: the Fell Foliage debacle, VP faction changes, the EoK blocker prerequisite, the armor progression being an extension of EoK, some previously successful guilds struggling with the new raid content — especially Drusella's Vault, the annoying drakes in SF, the DoTs cast by T1 mobs, and probably many other things along with server and instance instability to go with it.
However, overall, I don't think it was that bad of an expansion. There were many positives. After the success of EoK, I think many were hoping for a continuation of Kunark. RoS delivered on that and brought back many of the stomping grounds frequented by players in the earlier days. Cacti and Scorpikises made a return. It brought tradeskills back into the mix with a nice tradeskill quest for Crestra's earring. There were unique quested items from VP with ideas similar to that of the EoK ancients. Howling Stones was without a doubt my favorite zone in the expansion. Sathir's Tomb was a nice extension, but unfortunately, it was extremely tiny.
My favorite part of the expansion was probably that bards received some new stuff: Bellow and Shout changes, group double invis AA, intimidation, and I love the two new Blood Orchid Katanas with the Petal Step clickies (<3 leap!), which bards, of course, can use on the run. The skull of null clicky is nice one too. In addition to that, the missions were fun, the ST raids are a blast, and I got to enjoy some duration of fun running around VP with max ally faction.