Why do many former British colonies' flag still have a British flag symbol on their flag?

Question

Countries like Australia, New Zealand, and Fiji have the symbol on their flag, does anyone know why

Answer 1

Yes, it is in recognition of the fact that the British taught these backward countries how to be civilised.

A little gratitude would not go amiss.

Answer 2

I disagree with Ebenezer. It was done simply because the new designs were so empty, and the Union Jack looked pretty, was handy, and the graphic designer thought "ah, heck, that'll do!". As for teaching us civilization - sorry, that failed.
:-)