Plenty of Independent TV stations had 10 pm newscasts before the Fox, UPN (now My) and WB (now CW) networks debuted. If you think about it, 11 pm really is late for a newscast most people can watch, since most people are up by 7 a.m. and some earlier. It's hard to watch the 11 p.m. news and still get 8 hours of sleep.
So the Independent stations would run a movie at 8 p.m. and do news an hour before everyone else by airing it at 10 p.m. Then when the network stations were doing news at 11 p.m., the Independent stations offered an off-network sitcom as counter-programming.
KTXL was unique in that it was among the first UHF (channel 14 and above) Independent stations to do 10 p.m. news, IIRC. Most of the Independent TV stations with 10 p.m. news were VHF. But over time, as more TVs came equipped with UHF reception, those stations began adding 10 p.m. newscasts as well.