Who's not elected? Micro party candidates. You bet your arse they were. Most of the lower house seats are elected from a 30-40% base. Are they illegitimate, too?
I recommend you read Antony Green's view on it. He's my go to Psephologist. I don't believe there is any reason to think that it will tend toward one end or the other. The PR voting system will always through up the odd surprise, but it will always come down to the preference flows. When you analyse the results, though, typically something like 90% of voters see their first preference elected. (I'll find a source for that. Most of my old electoral wonk reading has died of old age :) )
Removing group voting tickets (GVT) and the need to fill in every slot on the card is the right fix. GVT's were a terrible idea to begin with and created the 'gaming' that were talking about. I believe it was intentional. What GVTs allow is for a niche candidate to direct their preferences to another 'mainstream' candidate, but do it in a quiet back room (read that as a pdf on the AEC's website) where most people won't look. So, more candidates leads to a huge ballot paper that everyone then complains about.
Make no mistake, the big boys invented gaming PR when they introduced GVTs. I've been trying to work out what the major parties get from this. All I can come up with is that the indies have got better at gaming it than them. Combined with a fall in their primary vote, or more to the point a higher vote for candidates they don't control, its just not working to their advantage anymore.
These changes are basically just a reversion to how it was until, iirc, the 70s or 80s. (Again, I'll source that) Don't let them tell you its a bad system. The big boys gamed it when they introduced HVTs. This is just changing it back.