answer

answer is "free will". by allowing the created to have a choice, the true value of the faithful is established, as compared to those having no faith.

if it were commanded and made equal that all MUST worship, there would be no meaning.

It is free will which defines the individual, and the Creator is much more honored by those who themselves by choice of their own free will do the honoring by their actions, as opposed to what the effect would be if they were commanded to worship, which, incidentally is the strategy of the dark side.

It is all about Free Will.