First of all, I don't appreciate your tone.
Second, this old firearms technology is all over the game, not just on Myrellion. The hammer pistol is a conventional magazine-fed gun that fires bullets.The "High tech" one Anno can sells you has the extremely far-future tech :captainpop: of armor-piercing ammo, laser sights, and a suppressor. Obviously, all things we have today.
Then we have Carl, whom you meet on Mhen'ga, and is the retired owner of a galaxy-wide empire of firearms manufacturing. What does he sell? A hammer pistol, a revolver (whose description, by the way, reads: " This is a large-barreled weapon of ancient design. Don't let it's age fool you - projectile weapon design hasn't changed that much with the passage of time. "). A sword, a machete, a warhammer, all low-tech kinetic weapons. His only high tech weapons are a laser pistol and a stun gun, and while those are certainly future tech, I think it's safe to say we're far away from Mass Effect levels of shaving miniscule bits of metal off of a block and accelerating them to light speed, here. I think it's safe to say that weapons technology is still subject to the laws of physics as we know them today.
I'd also ask why one would expect space pirates to have better technology than what's been developed by state actors, like I should take that for granted.