Because it's fun.
The Ammo/Ton isn't for the Machine-Guns, the AC2s, AC5s, UAC5s, RAC2 and RAC5s, no it's for the AC10s, UAC10s, AC20, UAC20s, the GR, and the HGR. Because it's fun slapping those in lights.
And while yes, I agree, the point of them being heavy is that they aren't really supposed to be carried by lightweight mechs. But they are fun, you have to sacrifice a lot to get a weapon there.
It will also provide more viability for the missile-builds on some of the lighter light-mechs, and bring playstyle diversity with chassis. The Locust 3S for example, the Locust itself is best ran with energy-weapons because it's so lightweight, you have better damage over a course of the match with energy weapon. But with it, if you double the ammo/ton of even the missile weapons, you bring better viability to light missile-builds, and thus provides more alternative playstyles.
Will it bring meta? I would argue not. Energy and Missile weapons will still be superior to a lighter mech. But it lends them viability and longevity, you can have your fun for longer, if it's not as effective.
If it's not going to ruin the balance anyways, why not just let people have their fun? Locust is a good example, the God-Quirked 1-E CT hardpoint, it's never going to be that viable versus alternatives, but it exists because it's fun.
Edited by The6thMessenger, 18 October 2020 - 01:42 AM.