The general trend with online forums, is that those with the strongest opinions are the most vocal.
Whether we like it or don't (and we're all much faster to point out the specifics of what we don't like), AIPA remains the largest aviation union in the country, and represents almost completely the Qantas pilot mainline pilot group. This Jetstar issue has highlighted the significant shortfalls of a narrow 'mainline only' approach, and will hopefully lead to wider representation for all, and a greater, balanced influence.
Continuing to segregate pilot groups into the AIPA, IPC, AFAP, and TWU, and actively suggesting pilots make a move to another union is only going to perpetuate the same sort of divisive issues that AIPA has faced over Jetstar.