This is a TV show, not real life. We weren't given a single bit of character development to remotely empathize with his death and, as such, that guy is a random nobody I could care less if he lives or dies. He's a "stormtrooper", for all intents and purposes. Same thing with the guards of the Fridge, Thomas Nash and most of the other people he killed. It's for no other reason that, of all the crimes he did, Coulson only ever uses Fitz's brain damage as well as Victoria Hand and Eric Koenig's deaths to justify his handling of Ward: those are the people that matter to the audience.
And not even those deaths hold that much weight when all is said and done! If, for example, we were suddenly presented a storyline where Ward moves heaven and hell to find a cure for Fitz's condition, acquires it and heals him to his former glory, the general audience would recognize his efforts and his slate would, for all intents and purposes, be cleaned for them, the deaths becoming a long distant memory. You can find quite a few examples of this in shows of the present, like Once Upon a Time, and the past, like Buffy and Angel. In fact, this is a Whedon trope, so you can sort of expect it at some point.