Sounds like a fair summary, but you haven't addressed what (I believe) is the key issue: OP feels bad.

pain [...] consistently high [...] don’t have the energy or enthusiasm

I think a huge turn off for "goal-setting" is that corporations do it, and also that they do it for the purpose of productivity. However, I'm not suggesting it for productivity, but for satisfaction. The satisfaction of completely something. Of climbing the mountain, completing the quest, bringing the elixir back, solving the problem, creating something new. I'm not saying one "should" do it, I'm saying it's a way to feel satisfaction, instead of pain.

The key idea here is that a goal not something to strive for, but a limit. Not to force you on, but to let know when you have accomplished something - when to stop! Now, if you're a perfectionist, you may say, "but there's so much more! I've barely scratched the surface. I've done nothing! I'm not worthy!"

However, if you had a goal, and you can remember how it looked when you set it (that it did seem challenging), then when you reach it, you can compare where you were, and where you are now. And you are forced to acknowledge the fact that you have accomplished something.

This gives a flood of satisfaction, like it or not.

Now, turning to "sprint" vs. "system". Firstly, I stressed that the goal must be doable. There's minimal risk that you can't complete it, if it is "doable". And if it's too hard, pick a smaller one.

Note also that you can shift topics between goals, just as you can with a system. I'm talking about small goals, not huge overreaching ambitious goals. Baby steps - but steps nonetheless!

Sprints seem very compatible with human psychology: movies, books and music usually consist of alternating tension and release. There's a series of difficult obstacles, not just one, but a series of problems and solutions. People really respond to this.

Curiously, it seems that literal sprints (i.e. running) are also much better for building fitness than consistent paces. And they even have "sprints" in some agile methodologies (not sure if that counts for or against my argument...).

Finally, there's absolutely a magic in programming, that you code something... and something happens! It's a child-like thrill that (in my opinion) it is absolutely crucial to respect and preserve, especially as ones goals become ambitious and abstract. Fred Brooks talks about the "sheer joy of making things" - and compares us both to a child making mud-pies and to God creating nature. (just found an excerpt online: http://cs.calvin.edu/books/processing/references/brooks/myth...)

I would guess that, evolutionarily, the human body and mind is adapted to sprints - and this is what makes goals feel so satisfying to us, just as we enjoy food, water etc. The "system" approach makes logical sense, and what you say about it seems true. It's just that you haven't addressed how it engages with human motivation (but assume it is "an automatic and permanent drive") - which is the issue OP is struggling with.

Lastly - I think OP's personal solution will actually come from the thoughts he has when he feels that pain. Part mistaken, part profound - only OP will know which is which. I don't claim my suggestion is right for OP, just adding another perspective.