I've grown up watching Star Wars, reading extended universe content, & playing many of the video games. (Any other related discussions I am totally up for regarding this topic!) Anyways, for some time I didn't think too much about the question above. Obi-Wan & Qui-Gon believed in Anakin, so I did too.
But if we're being technical, balance is an even distribution - NOT the light side winning over the dark side. Besides, Darth Sidious comes back in the original extended universe & Anakin's decedents end up fighting back anyways. So true balance would have been closer to the Jedi-Sith wars where each side had a significant number of followers. Another way to remedy this is having no force sensitive organisms. So technically Anakin didn't bring balance to the Force.
I'm not sure if anyone else has read about or heard this theory: it's implied that Darth Plagueis 'created' Anakin due to his mastery of the Force, so some think the whole prophecy was a Sith plot. Which makes sense considering the long game Sidious played to obtain the ultimate apprentice. Details of whether Sidious had learned this is unclear. Either way, this is more probable to me as an overall explanation than the Force collectively deciding to bring Anakin into existence to fulfill an impossible prophecy.
As an additional side note, the two polarized ends of the spectrum often reminded me of religion. Good v. Bad - saved v. unsaved. Maybe that is why I now prefer a balanced approach. Each side has pros & cons, but combining the best of both & straddling the line seems to be a better approach. Either extreme can be stifling in terms of growth & exploration. I've added an interesting comparison of such a comparison someone has made. (The neutral code reminds me of Assassin's Creed - not sure if that was intentional or not.)
Thoughts? Additional perspectives? What would be your preferred lightsaber color (canon &/or non)? Fun facts?
I'm not sure I actually believe what I am about to write. It's a thought exercise. Perhaps the light side and dark side are not intrinsically "good" or "bad." The light side represents hope and caring while the dark side represents fear and hatred. So we all experience pieces of the dark side from time to time. The balance lies in not giving in to it and letting it forever dominate our destiny.
I don't know if proper balance means as much evil as good, but I do know that Lucas consulted heavily with Joseph Campbell on important plot elements. Joseph Campbell was a scholarly gent who studied and lectured on anthropology and philosophy, delving a lot into the mythologies of mankind's civilizations. So, you'd then expect references to common archetypes such as the hero's journey, good and evil, etc. There's a good list of them here: [quia.com]
I know I'm not really answering your questions, but understanding from where these plot lines and characters originate sure explains the universal appeal of the franchise.