Let's engage in some truth-shining on your revisionist history, shall we?
UO - massive item duping issues due to how the item database was updated on patch intervals. Rampant player griefing, camping, etc... It wasn't until years later when Gordon Walton joined Origin and started his tenure by banning thousands of players did UO turn around.
WoW - Due to the network topology of 5(?) game servers sharing one item database server it took minutes....lots and lots of minutes for loot menus to appear after players killed animals/monsters/mobs, etc... Overloaded login servers also made for huge queues just to get into the game
EverQuest - The team launched the game and then went to Game Developer Conference for a week. The login servers crashed and continued to crash even then they were brought online. That situation existed for most of that week.
That leave AC and SW:G. AC did launch cleanly. SW:G I have no clue about with regards to its launch. The problem with SW:G was more of its base design poor support and half-thought out attempts to attract players by changing things at a moments notice to the detriment of the existing player base.
There have been clean MMO launches since SW:G. AC2 launched well but was poorly received. EVE did not have any issues that I remember. City of Heroes doesn't ring any bells, etc...
Not all other MMO launches have been shitty.