I don't think so. I'd call it a horrendous balance issue to allow a non military trained PC full access to very specialized weaponry skills at no cost (skill commitment).
Not really the topic is what happened to big guns skill, his first post seems to imply that this makes the game terrible and he prefers fallout 3.
I'd say it's a big leap to bash the entire game on the lack of one skill.
People who base their arguments about game balance on what is "plausible" or "realistic" in a game where you have coffee cup sized fusion reactors, flying robots and 15 foot tall bipedal lizards really, REALLY annoy me.
He isn't promoting a realistic simulator. He's trying to find some sort of reasoning for promoting balance and the placement of weapons.
I'd say you are overreacting.
I'm open to convincing, if you can explain a realistic reason why. I don't see how training with dynamite fusing, and C4 relates to training with a big kid's supersoaker. I could see overlap with grenades and dynamite if Throwing was still a skill, and the game used it for targeting accuracy. As it is though ~for some bonkers reason... Two guys can lob identical grenades at identical targets, but the one whose an expert in C4 does more damage with his.
For someone who promoted no combat options, saying that they shouldn't be that important, earlier you sure want a lot of combat skills. The same reasoning applies to laser based and plasma based weapons. Placing a mine isn't the same as a throwing a grenade and grenade launchers handle differently than either. (Which in hindsight you already discussed)
You are left with a veritable list of weapon skills, which are so specialized you probably need to pick another weapon skill to augment, thus leaving less skillpoints for non-combat skills or forcing a someone how doesn't value combat so much to the guns skill, which is wide enough to compete with all the other skills and come out on top.
'Fallout! We've got loads of combat skills.'
*Gauss certainly should not be classed as an energy weapon.
True, but guns already has it's BFG sniper in the AMR. Not to mention that Fallout 3 already got it wrong.
It's rather unfortunate. EW could have easily used some classic weapons to fill the gaps and a few gauss weapons might have spruced up the guns. But moving it now would be horribly unbalanced.