There were two major reasons why Woodrow Wilson was unable to get the Paris Peace Conference to implement his vision of what the peace treaty should look like. First, Wilson himself had an attitude that annoyed his fellow leaders and made them want to resist him. Second, the other countries (particularly England and France) did not share Wilson's idealistic goals for the treaty.
The first problem had to do with Wilson's personality. He seemed too arrogant and preachy to the other leaders. An example of this can be seen in the following quote from the French leader Georges Clemenceau (found in the link below):
How can I talk to a fellow who thinks himself the first man for two thousand years who has known anything about peace on earth?
By making his fellow leaders dislike him, Wilson made it harder to achieve his goals.
Second, the other leaders were not nearly as interested as Wilson in creating an ideal world. Their countries had been hit much harder by the war than the US had. They wanted a treaty that would either A) compensate them for the damages and expenses they had suffered, B) make sure Germany would not be able to make trouble again any time soon, or C) both. These desires made them oppose Wilson's goals.
For these reasons, most of Wilson's 14 Points, with the exception of the League of Nations, did not make it into the Treaty of Versailes.