As I understand Senate voting, if you are less than 5% you don't get to preference other parties with above the line voting. That means many votes for minor parties don't make it back to the majors.
LNP needs to be sufficiently Right to avoid upper house leaching to ON & AC, but moderate enough to win seats in the lower house.
There is also the issue of most of it's donations and manpower coming from the Right.
It is a tough ask.
