I disagree with the majority of this statement even if I'm aware of what you're trying to say.
Assuming anything about the skill level of the playerbase let alone anyone who actually raids is a recipe for disaster, it also discounts what motivates and helps various players learn.
This has been stated before but it might come as a surprise to you that there are many players who simply are unaware of how well they are or aren't performing and this goes both ways. There are plenty of players who lack the confidence to enter a raid because they think they are bad only to discover otherwise when shown tangible feedback (like a parse result) that they are better than they think they are and the results give them the confidence to attempt finding a raid group.
It has to start somewhere.
Like in a thread where a Ps4 player is asking for a personal parser so that they can improve.
Also I don't think it's ever been stated that adding a parser is suddenly going to add tons of capable players to the raid scene, but it might change the minds of a few that are on the fence, when they see their results. Likewise it might encourage others to practice a bit more if they find out they aren't as good as they think they are.
No, I'm pretty sure i quoted it correctly:
Practice (learning method)
language; like many other things evolves with time, if you only go by the origin of an idiom you are going to be left behind when it comes to modern day vernacular.
On to the point however, while the script of a fight itself doesn't change the actions of the players in the fight may. This has been illustrated by more than a few posters when it comes to things like phase pushes etc.
I don't think it's necessary for me to touch on this again when many others have already done so sufficiently.
It's almost as if a parser were a tool that displays data and feedback that can be used and interpreted in various ways for evaluation based on the needs and the skill level of the group using it, additionally it's almost as if different groups have various ways of approaching and learning content perhaps based on the fact that there are various players with differing ability levels, motivations, and schools of thought.
I would not compare the practices and methodology of a world first raid group to a fresh group of new raiders starting right now that needs to use youtube guides, spreadsheets, and power point presentations as they learn and attempt raid content. I also use the term "need" loosely as the group is likely capable of learning and completing the fight without those aids but if they choose to use them and find a benefit in doing so it's not really the place of myself or anyone else to tell them otherwise.
If it works for them, it works for them much like the data a party receives and interprets from a parser.
It's like saying just because you can do the math by hand means that nobody ever should have to use a calculator, it just doesn't follow.
This is entirely your opinion, perhaps you do not operate on some of these concepts but this does not mean others do not.
The forums (DPS subform in particular) are riddled with players asking how they can perform better in content or looking at their results and noting areas where they can improve.
If you're pro parser like you say, then why do you care about the reasons that someone wants it?
If a group of players is able to take parse data and use it for evaluation and improvement, not you or anyone else can claim that their reasons or methodology are wrong if it provides favorable results. It may mean that they were using it in a way you don't believe it was intended but if it makes positive change across the board then your objections are irrelevant.
Also I'm not entirely sure if you're trying to argue this in circles intentionally or not as many of the points you've raised have been answered already by many other posters throughout both this thread and the 80 page one in the DPS subforum.
Either way I doubt there's much more that can be said on the subject that hasn't been said countless times already, if you still disagree at this point I'm not sure I'm the right person to properly explain otherwise.