No, there's a massive difference. Taking Star Trek as an example: most of the time (not all the time, I am well aware), old Trek series were careful to present social commentary in a way that trusted the viewer to draw his own conclusions. The writers may have had an opinion, but they avoided obviously taking a side and tried to present reasonable points of view all around even if they did gently nudge things to make one side seem better. By letting the viewer come to a conclusion naturally, they actually had persuasive power because they didn't antagonize the audience. New Star Trek, on the other hand, has the writers openly preaching to you. They have one side of an issue represented by paragons of virtue, the other side represented by the scum of the earth, and have characters say what a bad person one must be if they come down on the wrong side of this. There is no subtlety whatsoever, and it has no persuasive power because the writers are more interested in flipping the bird to those whom they consider evil than actually trying to educate or persuade the audience.

And while I'm speaking specifically of Trek, this happens a lot with modern sci-fi. There is so much bad, preachy writing out there. And while that may have always existed to some extent, it wasn't the norm. Now it is the norm and it sucks.