Many religions and philosophers understand the idea that humans are not basically good people. They are generally self centered and not sacrificial. So to say that Catholicism or Christianity is strange for placing emphasis on our "fallenness" is a little unfair IMHO.
The daily struggle of a Christian is to strive to rid one's self of their sinful desires (selfish / evil) and live as Christ commands. This a continual process, and one that cannot be stopped. If one just "gets tired" of being a Christian, and lives differently, then they are in danger of losing their salvation.
I only go into this detail to illustrate that there is more to "Catholic guilt" than a flippant "critique".
How is this not a vehicle of control? It steers you in the direction of behaving the way Christianity prescribes for fear of the ultimate bad consequence which is losing your salvation.
Thanks for your perspective. You're certainly selling it better than the Catholic Church is. (You won't be surprised to hear that I'm not buying into the whole thing either way.)
The eastern christianity still recognises sin, but treats it more like a disease, the priest is more of a doctor.
I find this more appealing from a philosophical point of view, yet I lack any reason to believe.
The premise of Christianity is "revelation". That a higher power revealed knowledge to humans that is not knowable by any other means.
That there is revealed knowledge has meant that Christians spend much of their time thinking about and working out the implications of their revealed knowledge and trying to fit it into the rest of the world.
How rational you find Christianity depends on willing you are to accept it's premise. If you are then it is completely rational. If you aren't then it is nothing but castles built in the clouds.