Ok.
I know that Agents of S.H.I.E.L.D isn't canon in the MCU anymore, and am well aware of controversy. Before I continue I just want everyone to know that this is my OPINION and if yours is different, I respect it.
First of all, Deathlok is an amazing character in the comics and the many versions of him. However, it is very similar in my eyes to the Winter Soldier storyline. Good guy goes up against bad guy. Bad guy almost kills good guy. Good guy is experimented on by bad guy and turned into the fricking Marvel version of the Terminator. Good guy realizes that being the killer is bad and then rebells against bad guy
See where I'm going?
Point is, Agents of S.H.I.E.L.D didn't make this Deathlok thing happen until the end of the season. There could have been more creativity and more Deathlok himself.