Both of my recent idiot exes were horrified that dd , 6 does not sleep in the pitch black but instead has a night light and/ or dimmer on its lowest setting. Both of them called me a bad mother over it and both thought I should train her not to be afraid of the dark.
Whilst I think it's great if your kids are not scared of the dark, I also feel that it is human nature to be scared of the dark (historically vulnerable to predators at night) and that kids have vivid imaginations and that there is nothing wrong with a night light.
Also, as a single parent, I have much bigger fish to fry regarding parenting. IMO both were complete controlling knobs for insisting on pitch black and for calling me a bad mum. Uggggrrrr.