The parser as a tool is great, but like most tools they can be abused to inflict harm on others. I used to be an advocate supporter of parsers, back when they first showed up in World of Warcraft. I was naive and thought that this tool would encourage others to improve their gameplay and some of them did. Then I started seeing people saying stuff like you need to do Y damage per second or X damage per second. Casuals and Hardcore players started dictating how much dps a player should deal. Whenever someone failed to meet these standards, they were verbally abused and shamed. At first this was a small issue, it happend only to those that raid alot, then it started affecting the random players that joined the duty finder and played casual, they too got insulted and were told to meet the standard or be kicked.
I love to have a personal parser, because if I am able to improve myself, as a gamer, why shouldnt I? But not everyone has the same reasons as me and not everyone is as kind as the posters here who claim that the tool will only be used to help. The parser will be used to inflict harm and demean others, its already happening with ACT, I have seen players insulting others during a roulette and they saying stuff that makes it very obvious that they are using a tool to see the damage dealt by the other players. The only reason why alot of gamers are not using the data from the parsers, is because they are afraid of being reported and banned. If SE changes this and using parsers is allowed, then from past experiences in other mmorpgs, I can assure you that this tool will be used to insult and shame others and not to help. I have witnessed communities becomming very toxic.
That is why I want to have a personal parser, so I can improve myself and not one where others can judge me for it.
I can understand how having parsers will ultimately help when you are playing with friends, static and free company members, but I have to disagree that this tool will do more good then harm in the end when it comes to the playerbase overall. MMORPG like World of Warcraft have shown me that in general this tool wiill increase the toxic behavior of players, I have seen this in other mmorpgs aswell. If you are raiding with mates, the odds of them verbally abusing you or shaming you is very low, but strangers are not as kind.
You say that the parser will ultimately lead to more good than harm, can you share with us, where you got this from? Is it from a past experience and if it is, was it with friends or a whole community?