Quran does provide us with simple answers to complex questions. Most of the intolerance stems from ignorance and a false sense of self-importance, for example:
Jews are 'Chosen' - so, all will go to Heaven - regardless of what they did in their earthly life.
Christ died for their sins - so, all Christians will go to Heaven- regardless of what they did in their earthly life.
Prophet (PBUH) will be the intercessor - so, all Muslims will go to Heaven - - regardless of what they did in their earthly life.
For Hindus, we can do whatever in this life, will do good stuff in our next reincarnation - everything goes.
Quran - actually denies any special status given to any community and tells us that it's only good deeds that will lead us to Heaven.
Following verses are taken from translation of M.A.S. Abdel Haleem.
Each community has its own direction to which it turns: race to do good deeds and wherever you are, God will bring you together (on Judgement Day). (2:148)
The [Muslim] believers, the Jews, the Christians, and the Sabians–– all those who believe in God and the Last Day and do good–– will have their rewards with their Lord. No fear for them, nor will they grieve. (2:62)
They also say, ‘No one will enter Paradise unless he is aJew or a Christian.’ This is their own wishful thinking. [Prophet], say, ‘Produce your evidence, if you are telling the truth.’ (2:111) In fact, any who direct themselves wholly to God and do good will have their reward with their Lord: no fear for them, nor will they grieve. (2:112)
Also, in verses 5:43 - 5:49 Jews, Christians and Muslims are told to judge according to their own Scriptures; and that is prescribed even in the presence of Prophet Muhammad (PBUH).