The conditional provision was put into place to help deal with issues of marriage of convenience. There are provisions to deal with situations where a spouse, often a woman, is in a situation of abuse or neglect, but it is the case that it is a conditional status. If the marriage ends, the reason for which the person came to Canada, then their conditional status would lapse and they would be asked to leave Canada. The relationship was the reason they came to Canada, so in that situation, if the person doesn't qualify for other immigration programs, they would be asked to return to the country they came from where normally they have most of their family support. The family support that brought them to Canada has now ended.
That is the conditional status that was brought into place by the government.