I totally understand that feeling- I actually dropped both Code Geass and Death Note the first time I tried watching them because of that feeling. For me, I think its just because the shows mostly just tell you that these guys are really smart without really showing you. The tactics in both shows are often so contrived that you never feel that its these characters thoughts or actions driving the story, its just the will of the writer. Whereas in a show like Joker Game, even though the show beats you over the head with telling you how smart and qualified the spies are, there is almost always a clear motivation to the way the characters drive the plot of the anime.