Since I'm an old dude, and go back WAY before replay, I can say that I don't think officiating is any better or worse than it has ever been.
It's just that with instant replay and stop motion, and hi def, and all this technology that can zoom in on a finger and a blade of turf and can distinguish between the hundred of a second that the ball comes out (or doesn't) before a knee hits, and stuff like that, it unfairly makes officials look bad. They get one look, in real time, and don't have zoom lenses for eyes.
Plus, the rules have changed and there are more calls that are meant to protect players than there used to be. PI is called WAY closer than it used to be.
I think officiating is fine. Of course they make errors; they're human. But the vast majority of calls are amazingly good and backed up by replay. It's just the nature of the game that incorporates a lot of judgment calls.