Its third party vendors like Ticketmaster or stubhub showing them from corporate bought tickets online. Can't sell them? who cares and we won't budge on the price.
Unfortunately you are right about this. Nobody I work with gives a damn about the Rockets. Houston is a big city- full of transplants. The people from Houston seem to care about baseball and football a lot more than basketball. Yet Rockets tickets are still freaking expensive for good seats. Sucks.