This simply just isn't true.
For pure damage, I compare the nominal worst case: Energy Blast + Hammer Shot (the lowest damage GCD you should be using) to Gut used on a full cycle. Energy Blast + Hammer Shot actually deals in something like 20% more total damage than Gut will on a single target. If you're talking about target cycling (the Gut DoT isn't actually all that strong unless you go deep Tactics and are running in the proper Cell), you're screwing yourself over by draining your Ammo way faster than you should be. 1 target alone puts you pretty heavily in the red for Ammo maintenance, especially when you consider the required costs associated with Stockstrike and HiB on CD. While you might be able to do more damage with Gut in a *vacuum*, the practical limitations of VG tanking and the need to conserve ammo mean that you'll actually do substantially *more* damage with Energy Blast, even in AoE or multi-target situations where you could conceivably roll Gut on multiple targets.