Because it belongs to different and earlier part of history that for Aboriginal Australia began the false claim of "terra nullius" as well as leading to introduced diseases and many massacres. Jan 26 is hardly a day of celebration for them. Even as late as 1938, Aboriginal people in rural NSW were forcibly rounded up and made to reenact Phillip's arrival for the 150th anniversary in Sydney. Why stick with a fake date from only 1994 that deliberately divides us when most of us wouldn't give a flying firetruck about that date if it was changed to another?
Sorry you've confused me MT. What do you mean by "why stick with a fake date from only 1994"?
My entire life and I'm old 
Australia Day has always been 26th January. Granted it is only in the last 30 years that the public holiday has been on the actual date. Prior to that for reasons I will confess I never understood the public holiday was always on the Monday closest to the 26th.
As you say WP it was not a national public holiday until 1994.
And despite both of us being old
, it hasn't always been on Jan 26 either:
The last question of yours is easy to answer: a freebie long weekend in summer. Though few cared about the reason for it nor organised public events. The only thing I remember about that long weekend was the Adelaide test match but that was dumped long ago. So much for "tradition"!
And it's a fake day as Australia's real national birthday is 1st Jan 1901. Lying to ourselves and ignoring our own history and identity and not celebrating our own more significant achievements which are many is not displaying being proud independent Aussies.
