I think you're putting too much emphasis on achievements, to the point that it's taking away from your enjoyment of the game. What's more important? Your gamer-score or thoroughly enjoying a good video game from beginning to end.
I am of the opinion that, in some cases, achievements are hurting video games because developers put in some excruciatingly difficult achievements that people such as yourself will chase to the ends of the earth. Achievements were made to be a fun little extra you get for doing special things in games. As soon as they become a job and make you hate the game you are playing, they are not worth getting.