There is no wrong way to have fun.
I particularly dislike Hard SF snobbery from fans whose favoritate authors most famous books, FOUNDATION, STRANGER IN A STRANGE LAND, or AGAINST THE FALL OF NIGHT, routinely contain psionic and magical elements such as accurate prophacy of future events, superhumans with psychic power, humans angels, mind reading robots, faster than light drive, time travel, and other things that as about as “Hard SF” as a genii from a lamp.
I have written Hard SF — trying to imagine how a galactic or even intergalactic community could operate without faster than light unicorns drive takes some imagination, believe you me — and I have written pulp. I find pulp harder to write, since it takes more discipline regarding plot and pacing.
The difference is more one of structured versus improvizational use of the imagination than it is of better and worse. Pulp fiction is like jazz — within its highly structured limits, there is wide freedom for individualism, improvization, riffs and inversions of themes. It is governed by the Rule of Cool. You can have anything, including Space Princess or dinosaurs lumbering through the hothouse swamps of Venus, provided it is cool.
Hard SF is more like classical music. Hard SF has a structured limitation on settings and props, that is, the make-believe technology must have a figleaf of versimilitude as something that could plausibly grow out of the modern day undersanding of physics and technology. You can get away with magic if you call it psionics and say it is non-supernatural phenomenon. You can get away with faster than light drive because if you mumble something about hyperspace or inertialess drive or quantum tunnelling and say that it is a non-supernatural phenomenon. You can even get away with Time Travel. Because otherwise the Ghost of Christmas Morlock cannot show you the final fate of mankind.
The basic limit of Hard SF is the writer cannot violate no known facts of science: Venus is a sulferic hell with a temperature to melt lead, for example, and if the daughter of a monarch of Mars is going to look like a nubile maiden from Europe or India, except with bright red skin, there had bettter be some explanation involving parallel evolution or mutual interplanetary ancestors.
Now, working within these limits is fun, and it is fun to do research and get all the details of travel times and distances to nearby stars correct, or to make sure that what you are saying about higher mathematics or exotic matter properties or Einsteinian frame-dragging effects of rotating black holes is correct according to the latest theory.
But it is also fun to write about a nubile space princess being saved from an evil dinosaur of Venus.