All the people (see 21:43): This does not mean every living Jewish person. Instead, it refers to those who urged the condemnation of Jesus. They represented all of Israel who disbelieved Jesus. Their actions led to consequences for the entire nation, like the destruction of Jerusalem in AD 70.
His blood be on us and on our children! (see 23:35; 2 Samuel 1:16; 14:9; Jeremiah 51:35; Acts 5:28; 18:6; 20:26): Some Christians have misunderstood and misused this verse as a basis for persecuting Jews. But it is not a general accusation against all Jewish people.