Having to go to Central is a silly argument - most folks need to go to Central to connect to alternative services because there are insufficient North-South connectors in Sydney's public transport strategy.
For example I used to live in Kingsgrove just near the train station. Easy 20 minutes to drive, park and then walk to Leichhardt. To go via light rail I needed to go first to Central as you say. But also to get to Parra Stadium I needed to go first to Central. Penrith the same. To get to Homebush I needed to go to Central, unless I wanted to sit on the "special" bus for 60 minutes. For Brookvale Oval you may as well fly to New Zealand.
So being close to a train station is all relative depending where you are on the network. In that case the light rail is just as useful / available as any other service, depending on where you live.