1) Because that mod already exists, and while it was cool, it wouldn't effect enemy ships, was weak, and costs OP points.
2) Because I wanted to make armor-based ships able to absorb damage, something that shield based ships tend to have a monopoly on early game. I didn't like not having the option of choosing low-tech ships due to them dying to extended range beam weapons.
After enough times trying to use low-tech ships and finding them to be hilariously fragile compared to high-tech ships, I wanted to make them more durable in a somewhat fair way. This changed my playstyle to be willing to take damage, rather than being terrified of anything scratching my armor.
Most likely this is because I am a rubbish player, and there is a way to fly low-tech frigates without them melting to literally everything, but I haven't figured it out yet. Beams simply make it so that they get torn apart. They can't dodge, or soak it on their shield, meaning that you have to outrange the beam. A patch a while ago made that infeasible. 1k beam range is pretty much able to match the longest vanilla projectile weapon in a medium socket.
That said, I had to make it pretty weak compared to what i've seen in other mods, otherwise it makes combat significantly slower. I certainly don't want to go to the level that Vacuum did, with ships that were both nearly impervious to damage and repaired any armor breaches in around 20 seconds.
