The Oclis Zemo was an unusual second-class mech.
Back when Ves was still a humble third-class mech designer, he regularly came in touch with ballistic weapons.
In a society where laser beam weapons and many more advanced weapon technologies became available, the demand for the most basic ballistic weapons had never faded.
This was because more advanced weapon systems usually imposed greater requirements. These could range from needing to master more advanced knowledge, the use of higher grades of materials and the necessity of having access to a much stronger power source.
It was human nature to chase after the most expensive and powerful toys, but not everyone had the opportunity or the capital to handle them. In a cosmos where scarcity was a universal phenomenon, the ordinary masses could only dream of piloting the most advanced mechs or wielding the most destructive weapons.