CGI doesn't just piss you off? Ok a big film with a hundred million in effects is one thing. But endless scifi shows with increasingly annoying, unconvincing effects it just annoys. Not only does it generally look bad, but it encourages lazy script writing.
Why bother with tension or surprise when some spoddy geek with a dell can give you a 200 foot tall Trex (even if it looks shit).
I'll add examples when I can be bothered to look in YouTube.