Granted it is limits of set design, but this always seemed odd to me. The Federation has hundreds of worlds and Starfleet might have just as many species. But on all the starships we see are designed around normal sized humans without any disabilities. Temperature, gravity, pressure, atmosphere, light, room dimensions and heights are all set for that. It's little wonder that on all the ships we see humans are the supermajority, and of those who aren't, are really just humans with different markings/bumps on their heads and silly hairdos since that is all who are accommodated on our Hero Ship designs.
My headcanon, for species outside the 'norm', they are concentrated on other vessels that we simply don't see. We know from TOS with the Intrepid that there is at least a ship full of Vulcans. And Solok's crew from DS9 seems to solidify this. So it would make sense for ships out there to be made accomodate species 1 meter and under (we don't see them before our heroes would have to crawl through those interiors). Or ships that have completely brighter interiors, or the gravity cranked up etc. The Federation and Starfleet is as inclusive as possible, but that has to give way to biology. A majority of officers will serve on the ship where do not have to wear eye protection or lug around life support equipment