Is what J to the D and Barry said in last weeks streamcast. All right, I may have paraphrased slightly, for succinctness, but I have 2, no 3.... some points:
I know the game is amazing in its complexity, but what the abilities do ain't. For people who have played a computer game before the process goes something like.. Spend talent points, load new ability, try it on dummy/piggy/wolf > Like it, keep it, Done. > Underwhelmed, remove from bar, regret, reroll, regrind Done.
In later levels the abilities are often modified either directly by " Thorns just got Thornier" type talents or indirectly by new achetype tree choices, e.g. buff Support power by tiny amounts spending 6 to 9 talent points, then blamo gain +650 by choosing 3rd tree. The choices we make later in the tree often make SOME of the choices we made earlier irrelevant/sub-optimal.
The talents I choose ultimately, will need to support me/my team as I further the Throne war against other players, what I learn from Soloing or even Grouping cats/spiders often has little relevance to what I will be using the skills for end game. Perhaps if you can upgrade the mobs AI with long distance social aggro (calling some other cats to gang up on you in Cat channel), trying to run/teleport/stealth away at low health or even remembering to get in range before attacking (love the way Cats wave at you from 15m) or giving cats ballistas (a cat with a ballista? wait, can i play that race?). Alright joking about stretch AI goals aside, even if I do learn something by leveling slowly grinding dumb cats, what relevance does it have to either a Keep siege or a One on One encounter? Level to 30, turn up at keep/mind your own business, get smoked/ganked, regret, reroll, regrind.
Whatever I have learned about my abilities and passives gained through leveling, Disciplines - BOOM I just 8 to 11 more. All right, somewhat staggered in the leveling process (currently)***, but again, probably making my previous learning's and choices less relevant. (In full launch) Aquire new Disc that gives you ability X, enhanced, for free, regret, reroll, regrind.
On the other hand, if you have all 30 levels to play with (after you have learnt a significant amount about the crafting and gathering systems e.g. frames, (I certainly learnt a huge amount about crafting, gathering and skill training)) You are more likely to look ahead down the talent tree and make better choices, well, potentially, we are all idiots sometimes and the Discs discovery system will still change your mind after the fact. Regret, reroll, regrind.
I think it was Timmy Mallet who first said "If you are not part of the solution then you are part of the problem" ... or was it Bob Marley ? Anyway, you'll notice in the word cloud of the above points 2 are massive: Regret and ReRoll. Options.
Disclaimer: On the first Sac'd level or every Sac'd level pop up says "I am a seasoned pro and know what I'm doing/I have watched so much YouTube my eyes are numb and will not cry or whine on the forums if I mess this up. I am not a robot." Yes/No Buttons.
Regret pots: On creation each new toon gets X character/account bound respec potions that refund X, Y or Z amounts of telant points to respend in light of you post leveling learnings.
Sac-Back: OK, I made a mistake, turns out I am noob, or what I learned last week got changed, or I just unlocked an awesome Disc that has reworked my entire bar....i really should have tried this on Test first.... I can use a 'Dark Sac' pit to un-level and lose the offending talent points. Fiendish !
Cry moar: Certain activities reward a free complete respec of all talent points across all toons. A whining forum post longer and more whiny than this one, no less than 17 emails whining to support email address, a total of no less than 160,00 repeats of the same /cry emote in front of the Sac Pit in your factions temple.
Rage quit. A listen subroutine monitors the keyboard for the keystrokes that result from smashing fists or forehead into the keyboard and pop up a free respec option before the mouse is smashed against the wall.
Patience, young padawan: I need to chill the fnark out and wait. While gold Sac's are still in game and campaigns get longer a trifling 14k for 30 levels of common vessel will be a mere afternoons takings from my trader/guildbank. I'll have to ask Anhrez what he thinks the effects of longer campaigns will mean to vessel price, but Ill conjecture that if you can afford an Epic vessel, than you can afford double that to level it ! /shows the #anhrez light.
TL:DR? In an attempt to look at the issues and possible solutions of leveling on dumb cats, more questions were raised than answered. L2Read!
***Reference: 5.8.3 Leveling values and Discipline slot unlocks (from Test server 9/2/19