I think both you and the poster you quoted need to separate the issue of losing skills, from the issue of trying to solo group instances, or be simultaneously effective at buffing, debuffing, healing, and dps.
Losing access to skills, or combining multiple skill effects into new ones to reduce total skills (which i suspect will happen to some classes that get more 'pruning' done) seems like simplification for the sake of simplification, to me. Making it so you have to trait deep into the blue line for water lore to stack at all would not simplify the class, but it would make it less able to have it all. Similarly, halving the duration of various debuffs, or dots, or sticky gourd unless traited specifically for it (and not being able to trait for all of this) would not simplify the class, but it would more effectively prevent classes like Loremaster, Warden, and Captain from having their cake and eating it too, which in large part they can do right now.
Since all we really know is that skills are being pruned, and have no real concept for how limiting the new trait trees will be, the exact opposite of what I suggest might become the reality, for all I know.
turbine are simplifyig things that dont need simplifying....llike i said earlier if it ent broke dont fix it. Classes that are currently versatile (like the ones u mentioned) wont be when the changes are implemented. They will have to stick to a certain role...whatever....and with the current set-up of PISS EASY RAIDS.....PISS EASY INSTANCES....PISS EASY SCALED INSTANCES....how the hell can tirbine justify even conemplating making things easier. Captains MUST either heal/dps/tank (Blue/Red/Yellow), same with all classes you mentioned....turbine are taking away the fun of 'hybrid traiting' like we do now to be versatile...YES good in practise as it makes people ASK IN GLOBAL FOR THE SPECIFIC CLASS NEEDED TO FILL THE ROLL. But we all know that no new instances/raids are coming...so once again i ask why?
If new content was coming that needed the changes then yeah sure......bring it on for new instances/raids....but tirbines focus is on solo end-game...which has no need for champion/captain tanks or whatever, just using them as en example, so once again why change?
to sum it up theres no new content that needs the changes, or content coming. One of the fun things about lotro is the versatility of classes at various times, thanks for taking that away