People visit each other, socialise, booze, gather as families and friends, drive around aimlessly after working hours, not social distancing. Now they aren't able to. If there is traffic all over the place 24/7, there are not enough police resources to monitor. Now if you are wandering around after 8pm, there are a very small number of reasons to be out and about.
More news tomorrow of industries that will be closed/limited. If you listened to the presser they are reviewing impacts on other states and import/exports an more than a dozen other factors. Melbourne has the largest port traffic in the country. If it closes other states will not get their supplies, national wide chains will suffer and not be able to trade. Things aren't as straight forward as it appears from the comfort of armchairs.
No conspiracy theories please.