I don’t know if this can be defined exactly as an unpopular opinion, but I think that the “Force balance” has a very precise meaning. In my opinion, “Force balance” means two things at the same time: 1) the destruction of the Sith; 2) balancing the Jedi path with the natural human desire of personal love and attachment.
To reach the Force balance the Sith must be destroyed, as they cause imbalance. The Sith don’t submit to the will of the Force and don’t respect the laws of nature, but try to bend the Force to their will and use it to create things that violate the laws of nature, for example the various monsters created through Sith alchemy during the Old Republic Era, or Darth Plagueis’ experiments with the midi-chlorians. Therefore in order for the Force balance to be restored the Sith must be destroyed, as they cause imbalance and the Force rejects them. This is why the Force created Anakin in Shmi’s womb and this is why the Force has a Chosen One who is destined to destroy the Sith. As explained in the Darth Plagueis novel, the Force created Anakin in Shmi’s womb because Darth Plagueis’ experiments with the midi-chlorians had led the Force to become unbalanced, then the Force itself reacted automatically by creating Anakin in Shmi’s womb in order to destroy the Sith once and for all, as the Force was tired of being continually brought into imbalance by the Sith. So, the Sith are a cause of imbalance and must be destroyed in order to reach balance.
However “balance” doesn’t only mean the destruction of the Sith, it also means being able to balance the Jedi path with human passions and emotions. Feeling affection for other people, falling in love and wanting a family are perfectly natural things, they’re part of human nature and the nature of many other humanoid species in the Galaxy. To forbid these feelings is to violate the laws of nature, so It’s a mistake and it’s a cause of imbalance. The Jedi made a great mistake by forbidding the members of the Order to experience these purely natural feelings, because forbidding a person to fall in love and have personal affections is like forbidding a lion to eat meat. It’s unnatural, it doesn’t work and it just creates problems. In fact, in the old EU it’s shown that many Jedi have attachment-related problems, because they felt feelings they were forbidden to feel, and so many of them often felt chained and imprisoned in themselves because of this. Therefore, balance doesn’t just mean the destruction of the Sith, it also means being able to express yourself through your emotions and attachments, but without letting your emotions dominate you. In other words, it means allowing the Jedi to experience the normal feelings of individual love and attachment, but without letting these feelings cloud their judgment.
So, why is Anakin the Chosen One and how he brought balance? Simple: through his fall to the Dark Side and through the Jedi purge he opened the eyes of the Order and made the Jedi see what they did wrong, in fact, after the Battle of Endor and the re-establishment of the Jedi Order Luke allowed the Jedi to have families and affections, letting them to be freer and to be at peace with themselves and balancing the Jedi path with the natural desire of personal love, affection and attachment. In addition, through his redemption, Anakin destroyed Darth Vader and Darth Sidious, destroying the Sith Order forever.
So, as Yoda suggested in Revenge of the Sith, the Prophecy was misunderstood. The Jedi were partially wrong about the meaning of the Prophecy. The Jedi of the Prequel Era were right in saying that the Prophecy foresaw the destruction of the Sith, but they were wrong in believing that they were in balance. The Jedi stopped being in balance when they forbade attachment and love (after the events of the Tales of the Jedi comics) and returned to be in balance when Luke Skywalker, the son of the Chosen One, implemented his less dogmatic and less rigid ideas and built the New Jedi Order.
This is in my opinion the most complete and coherent interpretation of the Prophecy and the meaning of the Force balance. Unfortunately this explanation can only work in the context of the old EU, and only by eliminating the Dark Empire Trilogy and basically everything that comes after the NJO series. However, I think it’s worth it.