"FC Groningen in the Eredivisie brought the Sydney-born star over to trial for them – but Jamieson admits he couldn't wait to get back to the Reds and his cushy A-League life. " 

This encapsulates in many ways why so so many players come back & why so so many players don't test themselves.  The A League is a holiday camp compared to European leagues & it doesn't make you a better player in 90% of cases.