Sunday 7pm is just not ideal for any segment of the local market, despite it being a good time for TV. Fridays and Saturdays at 7pm might suck for families too but at least they suit some people - those who want to drink and get raucous. Sunday afternoons suit families but not the drinking raucous types as much. Sunday evenings suck for everyone
I still remember the game Phoenix played on a Sunday night, away in Perth. I doubt SKY got many viewers in New Zealand for a game that finished well after midnight on Monday morning.