Sunday schedule

We know that on Sundays and holidays public transit starts its day at 7 AM. The Millennium Line doesn't have any train leaving its VCC Clark terminal until the first west bound train from the Lougheed Mall Station arrives. Consequently there is no east bound train until 7:30 or so. In the meantime east bound trains depart from Lougheed Mall Station on a regular basis. Translink has these empty trains waiting on the track between Production University Station and Lougheed Mall Station. My question is why not have earlier departures from the stations between VCC Clark and Lougheed Mall?