She's really not that different from the original -- just a different mix of the same traits. Despite the silly line Gary Oldman delivered in the movie, Dr. Smith wasn't really "evil" in the sense of active malevolence toward others, just a narcissistic coward and pathological liar who'd do anything for his own safety, comfort, and satisfaction, maybe feeling a twinge of regret if it brought harmful consequences to others, but still feeling justified in doing it anyway. (He only sabotaged the ship in the pilot because he was going to be paid handsomely for it, and he expected the loss of life to be remote enough that he wouldn't have to face it directly.) That ended up being mostly played for laughs in the original show, but the new show has found an interestingly different way to put together the same essential set of attributes, which is impressive.
Did you watch the series (or movie)? Smith was there to KILL the Robinsons by having the ship be destroyed by the robot. That's Evil, remote or up close.