The most interesting thing about the argument, is that there are probably quite a few fans who would argue that Star Trek is superior to Star Wars for literally this exact same reason.
The fact that Star Trek is grounded in our own reality means that the stories it has to tell are more relatable, since they all still take place within a more realistic world.
However, if we really examine the basic structure of the argument as to why Star Wars is better than Star Trek, it all seems to come down to the idea that Star Trek limits itself by being set in a world that, more or less, matches our own, while Star Wars is much broader due to the fact that it delves into the area of fantasy and mythology.
Scraps: Jordan Schlansky's Masterpiece | CONAN on TBS