The point is that people who are obsessed with vengeance or greed do stupid things that lead them to their deaths.
I agree. Also, we must not forget that Carlo was a fool. I mean, he even started fighting with Connie in Vito's house (deleted scene). He was having affairs, he ruined the business he was given by the Corleones.
And even before the beating he was humiliated in front of the Corleone family members. He had to sit in the kitchen with the women while the Corleones were talking business with Vito. Sonny humiliated him at the table (probably not the first time).
