Which also reminds me of another observation: why does each Trek race now only has a single planet ? Romulus getting destroyed by the Hobus supernova apparently made Nero the last of the Romulan empire, and apparently Vulcan has no colonies until New vulcan. Weird. Isn't one of the points of space travel is spreading around ?
Races are spreading around, but travel and reproduction are slow processes. It will take centuries before off-planet colonies grow to millions and billions, especially if they are reproducing at the rates of a present-day developed countries, the infrastructures and cities on these colonies don't pop of nowhere and take time to be built too. I find the ten thousand figure a bit too small, but perhaps Vulcans weren't fans of colonies. I also think it was confirmed at one point that the ten thousand figure was of people surviving from the destruction, and did not include Vulcans living elsewhere. Perhaps the colonies they already had weren't suitable to be a home for the entire race.
But you can't complain there weren't enough planets depicted in the films. We saw Earth, Vulcan, Romulus (in footage), Qo'noS, Rura Penthe (in deleted scenes), Saturn, Titan and Delta Vega. These were plenty, unlike Earth locations.