Is it true that monks are not to touch women because women are impure?
One of the practiced customs is that women are not to come into direct contact with monks applies only in Thailand. There is no such prohibition found in the Vinaya. In the Tripitaka when Ananda asks how a monk should behave towards women, the Buddha was made to say "Stay away from them," and if they should confront women "they are not to look at them." If this instruction is true we have to take it with a grain of salt.
It is possible that this instruction is meant only for Ananda. As we know he was a good looking monk and had a charming personality. At one certain instant he almost lost himself to a seductive woman but the Buddha intervened and saved him. The teaching might also be taken, as general instruction when we understand that most monks are still not enlightened beings. Should they be allowed close connection with women, they can easily become confused. To avoid being side-tracked, monks should keep clear from women. But not having direct contact with women does not imply impurity an inherent negative quality in women.
The Buddha himself never had to avoid women. He received them at every appropriate time because he was enlightened having transcended any sexual inclination. There is also more positive passage in which he recommended monks to treat women the same age as their mothers the way they would treat their mothers, etc.
How can the four groups of Buddhists work together as foundation for Buddhism when women as half of the population are always excluded? If women are weakened in supporting the Sanghas, Buddhism also becomes meaningless as it is used as a tool for liberating only the other half of the population. Both women and men must come together as established by the Buddha in supporting and promoting Buddhism.