What was Vatican ii?
Why was it needed?
Why do people hate it so much?
Vatican II updated some practices in the Church to make it more adaptable, empowering the grass roots.
People hate it because it happened at the same time there was a massive falling-away from all major denominations of Christianity in Western Culture, and they think Vatican II was the cause.
In reality, Vatican II didn’t happen in Protestantism, and yet many Protestant denominations suffered similar modernist heresies and a loss of faithful at the same time. Orthodoxy has suffered too where it exists in more Western countries such as Greece. In the Catholic Church, Vatican II was abused by liberal clergy, and they hid behind the adaptability it permitted when introducing their own erroneous practices. Vatican II was not meant to do away with traditional Catholicism, but many liberal bishops actually forbade traditional practices.
Nowadays, the modernists in the Church have exposed themselves and have been mostly unable to pass their false beliefs onto the new generation. They are getting old and their influence is waning. We’re seeing a slow, but gradual return to traditional Catholicism, but existing concurrently with the more positive Vatican II influences.
There are problems with the documents of Vatican II themselves in that they are a little vague and are open to interpretation. But it does not represent a departure from doctrine, and Papal authority has gradually been clarifying the spirit in which Vatican II is actually supposed to be interpreted. And that is the spirit of traditional Catholic teaching.
In any case, the 60s are well and truly over and the Church will go on. Although the Devil has used Vatican II for evil, God will not be taken for a fool and He will turn it into goodness in the centuries to come, which is a short time in the time scale of the Church. We must trust in Divine Providence. God knows what He’s doing, and He permits trials from the Evil One so that good may come of them.