So many people are missing the point, and hopefully ArenaNet doesn’t too. This is a damage based game. If the weapons in the game didnt have stats and damage ratings, and there wasn’t a DAMAGE METER above your enemies head every time you strike them (to let you know how much damage your doing!), players would be completely lost on which gear is better than other gear.
It IS competitive, and being the game is a MMORPG the most important competitor is yourself. You’re playing to improve your character, and nothings wrong with analyzing it through data, be it damage per second, healing per second, or any per battle statistics.
Also, the original poster is not asking for a exact version of WoWs Recount add on. Just a postmortem way to analyze the numbers that are happening very rapidly during battle.