There are good reasons to use short-range weapons.
One is to avoid damaging fragile living quarters. The International Space Station I know well from several tasks I was given at Boeing. It is basically several tin cans stuck together and their structural integrity is partly the result of internal air pressure. Newer space structures actually will be inflatable.
And it is small. In the central tube, the largest volume of the ISS, there are only eight feet between the walls. Even space and planetary habitats centuries from now may be fairly flimsy, because carting or creating structures off our very forgiving planet will require they be as material-minimal as possible.
A related reason is to avoid hurting innocent non-combatants and your own police/military. This is a big issue in police and military operating in nominally friendly territories. This is why certain ammunition is banned by police departments. You don’t want bullets to pierce buildings and kill people literally miles away. This is why increasingly smaller bombs are a big market for those making munitions. You want to take out small groups of terrorists and not entire city blocks.
Another good reason for short-range weapons is that they tend to be more compact. Which means cheaper (less material used in their construction). It also means lighter, for even a few pounds gets heavy after a while – especially if accompanied by other equipment such as extra ammunition, comm gear, restraints, etc. It also means concealable, important if you are a plain-clothes detective, under-cover cop, or spy.
Now we get to “light” sabers – from the viewpoint of someone who would actually design such things, and because I’m a systems as well as software engineer who would design their use and the training in their use.
The Star Wars kind are obviously not lasers. They are some solid material, or force fields or such which act as solid materials. Otherwise when opposing blades strike they would simply pass through each other and could not be used defensively. I can imagine a team of engineers sweating and brain-storming because the new quick-to-market product HAD to act like a solid even though it was immaterial!
Force sabers as depicted in movies and books are also compact, basically handles until switched on. Another win for force sabers – or forsabers as they might quickly become called. They might be very compact, basically a pencil until turned on. This would be a case of the pen being as mighty as the sword – because it IS a sword!
And why the brightly lit “blade”? Wouldn’t you want some strong visual feedback if you wielded something which could cut through steel and woosh all your air out into space? Or lop off your own body parts if you were clumsy? (The damned things had better have on-switches which have to be continuously depressed in case you drop them!)
See? George Lucas isn’t some ansy-pansy film maker. He is a visionary engineer!