Wow, that just sounds incredibly awful and not fun. Glad they changed it.
I dunno, maybe because like 20 people tell you death claws are not to be trifled with, even the Gun Runners (who own chainguns, plasma cannons, and rocket launchers) can't even get rid of them, and they're the result of pre-war experimentation?
If they weren't able to one shot them and you were able to just walk into their layers and kill them easily it would take out all of the tension and suspense that comes with killing a death claw.
When I got the quest from the Gun Runners to get rid of the deathclaws I was scared stuffless. I had to blow all of my money on a good new set of armor, around 20 stims, and a ton of ammo for my .223 pistol. Turns out I needed it all. The mother death claw really forgeted me over, and by the end of it I was all out of stimpacks and Ian was dead.
However, what I got from it was the opening of a supply route to a group of people that needed the guns desperately, and I got a pretty bit of experience too.
Going into dangerous engagements that are forewarned to be incredibly dangerous should not be easy, whatever your definition of gun it.