That's actually rubbish. The main reason their lines are better is because they operate with a lower house edge that pretty much every other bookie.

Most bookies book coinflips at $1.91 ($1.85 for TABs). Pinnacle gives $1.952.

Pinny does take positions, but not because the 'owner' likes a certain team. The book is just very sharp. Your money is safer at pinnacle than in an aussie bank account.