DiCE designed Specialist to be a "camping asshole"

Nah. They initially designed it to be the "glass cannon" it should be, but because Infiltration allowed good all-around PvP players to slay a little too effectively, against what was likely a lot of very potato players in the beta. It was over nerfed into the ground and thus rose up the "glass camping asshole".

Honestly, all infiltration needed was getting rid of the cool down reset on kills, especially since that's essentially a star card now(one that actually loses the precise mini-map, so it's even more balanced). The high TTK of it was great the way it was, as it was really only good if you hit headshots, and if you missed you were pretty screwed thanks to 100 health. But that's always the risk you take when playing glass cannon in literally anything.