10 Reasons Terminator Genisys Isn't As Bad As You Think
4. The New Terminator Type Made Sense
Since one of the biggest flaws Skynet has encountered has been their Terminators not quite being passable, the new Terminator - call it the T-3000 if you want - makes a certain amount of sense. Remember, dogs could easily pick out the first generation Terminators (something Genisys wisely utilized again early on in the film).
The T-1000s were better, but weren't about to pass a blood test, and couldn't absorb the memories of their victims. While Salvation was pretty much ignored by Genisys, Marcus obviously wasn't a big help to Skynet either. He passed the blood test, but couldn't be controlled in the end.
Which leads to John Connor/the T-3000. Essentially assimilating John Connor, it's a lot more human, with all of Connor's memories. Its blood is pretty much synthetic, but could probably pass for normal human blood at first glance, and it does get to keep all of Connor's memories, while still being a Terminator under Skynet control.
As far as the evolution of Terminators is concerned, it's actually a logical next step. Far better than the T-X, which wisely isn't mentioned anywhere in the movie.