There is nothing inherently wrong with the use of CGI, but it should be unobtrusive. Check out Blue Bolts work in Game of Thrones for example: https://www.youtube.com/watch?v=uhG1i_BobWY
The problem is directors nowadays overuse it - entire films can be filmed on a green screen and therein lies the problem. When an actor is facing down a CGI 'giant robot x' or engaged in 'high-speed jet bike chase' etc, it's impossible for an actor to convey those subtle cues that humans pick-up on because it's not really happening to them and on some deeper level we, the audience, can tell.
In days gone by, those hints were conveyed because some set designer had actually built a life-size replica of the monster and when the scene was filmed, the actor / actress was actually facing it down. I mean, take Signory Weaver in Aliens 2 at the end where she's facing down the queen in the nest. That was a real model, and it must have been pretty frightening when the animatronics crews were operating it, even thought it wasn't real.