Dan
Snicker... Snort... Chortle... GUFFAW!!! ROFL!!!. Danny boy, nothing you have to say regarding the Catholic Church is "plain sense". That you have the effrontery to style your snide, sarcastic, and dishonest question as "plain-sense" reveals much about you, none of it good.
I'll answer, though, for the sake of lurkers. Stripped of its illogical baggage, your question is "How can the Church founded by Jesus of Nazareth, the Christ, the Son of God, have sinners in it?" I suggest you ask Judas Iscariot, he might have an answer for you. You might also ask Simon Peter. He might have some insight into the matter. Jesus promised the He would be with us, His Church, always, and the the gates of Hell would not prevail against His Church. He didn't promise there wouldn't be a few evil people amongst us.
AB