(13 Nov 2020, 1:54 pm)Andreos1 wrote Do they not have enough opportunities to make their money during the day like? 
Unethical to take even more from the public purse in my book.

To me, it's not unethical at all. 
From an environmental point of view the more services they can run with their more efficient vehicles the better, and if it takes an incentive from the government to do that, then so be it.