Acts 21:21 but they have been informed about you that you teach all the Jews who are among the Gentiles to forsake Moses, saying that they ought not to circumcise their children nor to walk according to the customs.
Why would the Jews complain about what Paul was doing to the people outside of Israel? Why should they care?
Because they had built up their following based on rules and regulations rather than on God, His Son and His Spirit!
We do not have to follow the old rules and regulations about offerings and sacrifices because Christ is our perfect and complete sacrifice.
Follow God and His rules. Follow Christ. Follow the Holy Spirit.