I've crusaded for the Forge before, and now I am being called to its defense again...

The Forge is inaccurate. With the quake during charge, any kind of long range shot is a pure crapshoot. In fact, against all logic, it isn't even hitscan. You have to lead a shot that supposedly moves in excess of 6k meters per second. Plus, it is useless as an Anti-Personnel weapon.

The Forge is slow. Charging requires you to commit to a slow pace, and an inability to adjust for moving targets getting behind cover. It takes six seconds for the Breach to charge, and those six seconds render you immobile. It takes three for the standard, which you can hold, and 2.5 for the Assault, which must be fired at the moment of charge. (I may need to get these numbers again, I was a FG user back in E3 build before they were nerfed.)

The Forge is weak, to an extent. The normal variant can't even oneshot an LAV without some serious damage mods. Its DPS (if my numbers are right) is 400 per second. If you fire at the moment it charges and the shot always hits, which it has a 40% chance to not do anyway. 350 dps for the breach variant.

The Forge is expensive. ALL Heavy only equipment is twice as expensive as any comparable lightweight device.

The Forge must be manually aimed. It isn't lock and forget like its lightweight counterpart. It has an accuracy rating of 60%. Almost half the time, no matter how good a shot you are, that sumkitten will veer wide.

The Forge requires a heavy suit. A heavy without something to scare off infantry at medium range is an expensive prize turkey for any enterprising Assault Suit.

The Forge is meant for AV combat. It IS the face of intelligent AV that isn't a vehicle. It has zero application in man-to-man ground fights.

The Forge is a modified mining laser. That is badass.