TMP and TWoK at least had rank insignia for non-coms as well as ensigns. TOS and NuTrek can't see the point. They think nobody will be paying attention to that sort of thing.
Star Trek in general has never bothered too much with enlisted rank insignia. Chief O'Brien wore Lieutenant's pips until S6 where he started wearing the single hollow pip he continued to wear until season 4 of DS9 where we saw an actual enlisted rank pin.
Enterprise did have enlisted rank pins in the first season, but they gradually disappeared over the course of the series.