A productivity system that doesn't make you feel good about your daily life is not be sustainable in the long run. It doesn't matter how effective it is, that's not a life you want to be living.
What makes you feel better about your daily life will depend on your temperament. The author of this blog post found that GTD resulted in his feeling like he had a never-ending river of stress ahead of him. GTD failed for him.
Another example where GTD fails is for anyone who is doing sustained creative work. As Paul Graham describes in http://www.paulgraham.com/makersschedule.html, it is very important for those people to have large blocks of time set aside for focused work. GTD's focus on breaking things into simple tasks whose execution is routine is the antithesis of how work needs to be organized for a maker.
That said, GTD is life-changing for many people. If it works for you, by all means do it. But don't make the mistake of trying to convert everyone else to it. It isn't always right.
Why can't create tasks work in GTD? GTD methodology doesn't say that you HAVE TO break everything up into 2-minute chunks. It can be 2 hours set aside for creativity.
Saying "X doesn't work for everyone" sounds nice, as does "everything in moderation." But I get skeptical when someone uses "everything in moderation" to excuse their smoking habit, or "___ is NOT for everyone" . Hundreds of years ago I'm sure there were people arguing that "reading and writing is not for everyone." Eating vegetables is not for everyone, etc.
Also your belief that creativity can be scheduled in 2 hour chunks demonstrates that there is a lot you don't understand about creativity.
What I mean to say is that meditation works for everyone, even though there are many people who have tried it and concluded that it does not work for them. But we know that meditation works for everyone because we have studied it enough to see how it is fundamental to the way every humans' mind-body operates. For thousands of years, before science, I think many teachers of meditation knew in their hearts that anyone could learn how to meditate. And many others knew it in their hearts that they could not learn how to.
Maybe I'm wrong, and there is no way we can read each other's minds, but what if a system like GTD, maybe not even specifically GTD itself, was also fundamental enough to work for anyone? The way David Allen presents the system, which can be in a very elitist tone sometimes, is that GTD is all about doing what we already do as people, but in a differently-ordered way.
As for addressing that creativity can be scheduled in 2 hour chunks, I was not correct in making that flaky statement and you are right to make a point of it.
> Though I still appreciate some of GTD’s principles (next action, desired outcome as project, brain dumping, etc)
His issue is with GTD as a complete approach, and I very much agree with him. And while David Allen himself might give his blessing to 'partial' implementation (although his comment on the article suggests otherwise), the most common response I get when I talk about taking the best bits of GTD is that GTD only works if you implement all of it.
And I actually agree with that. I've 'religiously' applied GTD for years, but I kept falling off the wagon and forgot to do my weekly review, or some other crucial part of it. And without exception, the results were disastrous. Sure, there's bits and pieces that are useful, very useful maybe, but they're isolated enough to not be considered GTD anymore. If you do next actions the GTD way, you pretty much need to do the weekly review the GTD way, and you pretty much need to keep tabs on your inboxes without leaving any slack. That in itself can work against the more creative professions.
> So as long as you collect everything out of your head and into a system where you can review and prioritize, that's GTD for everyone regardless of your station in life.
If that's GTD, then I'd argue most productivity systems are GTD. Which makes GTD an empty signifier.
On a more positive note: even though I abandoned GTD as a whole, I did learn a lot of valuable things. And it did work very well in certain periods of my life when I had a lot of disparate things on my plate. And I might very well start using the system again if my work becomes more managerial or otherwise fit for GTD.
tl;dr: GTD in any meaningful sense means applying it as a whole. That's what sets it apart from other approaches. And for many of us, it doesn't work for a variety of reasons. For others it does, and that's okay too.