It’s a sci-fi, so why do most of the guns shoot bullets? That’s old technology, right? Not really. The bottom line is, it’s cheap technology. In The Khekarian Threat, Sevi has an energy-blaster that can do great damage (and does). Then again, she’s an elite soldier bodyguard for a Khekarian VIP and you would expect her to have all the high technology she might require.
The Good Guys, on the other hand, have low tech projectile-firing weapons used sparingly. They are not fighters or shooters or hunters. They don’t need fancy high-priced guns. They didn’t expect the battle they ended up in.
The truth of the matter is that ordinary people the world over don’t have the latest and greatest in all things. If cash is tight, people just won’t go for expensive unimportant things, especially when cheap will do. When things are really tight, of course, you don’t get the best in the important things, either. People make do according to what they can afford. It’s been like that down through the ages, and I would expect the future to be no different.