I think the primary rationale for eliminating this is that it's duplicative. There is provincial and territorial labour standards legislation applied to these workers. In this instance, it's a federal standard that was established in the 1930s at a time when provincial labour legislation was much weaker. At this point, it's just establishing a layer on top of provincial and territorial legislation that duplicates much of what exists in provinces and territories now.
On May 17th, 2012. See this statement in context.