Star Trek has never obeyed the rules of gravity, since the ridiculously rapidly decaying orbits of TOS. Your insistence that it start obeying real orbital mechanics now, something it never, ever did before, is completely arbitrary.
As a Doctor Who fan I take psuedo-science in my stride. I linked to an article exposing the [lack of] science in Star Trek.
I actually think it would have provided a cooler visual if the laws of gravity had been even slightly adhered to, with the Enterprise streaking across the sky in a decaying orbit as opposed to tumbling like a big sack of spuds.