Australian national broadcaster ABC has projected three states voted No, effectively defeating the referendum.
No, it is not just racism. There would have been an element of that, but it’s certainly far from the main reason. That idea is contradicted by the facts that a very significant portion of Indigenous people and Indigenous activists voted against it.
Linking to this useful post, explaining why various progressive groups were against it.
Significant proportion, but a minority still.
But yes it’s not racism alone, also confusion, selfishness, disinterest, spite, partisanship, a long list of reasons