I'm with you... to an extent.
I don't want to assume that everyone learns like I do, I'm sure that isn't the case, but I'm sure a fair bit of people do. If you dropped me into a 70 job I wouldn't know which way was up because part of learning a role is playing it through the leveling process. There is a reason so much controversy surrounds jump potion users.
To me having a parser available from the beginning of leveling a class is part of my desire to have them in the game. To be able to see the different ways new skills impact my DPS as I gain those skills would be really helpful.
As someone who really wants a parser for personal growth/improvment I don't see why we would limit it to endgame content - I can be doing a full rotation (for any level) on virtually any boss in a dungeon and I'd like to be getting the feedback a parser provides on all those encounters because it's always advantageous to know more and be able to edit as you go as opposed to reaching 70 and entering an EX primal only to discover you've been performing something incorrectly for the last 69 levels.
I say this as someone currently seriously considering purchasing a computer to run this game on despite not having more than a tablet in years literally just for the benefits of ACT.