The Judaizers at Galatia pandered to the Jews in the region. They wanted to make a "fair show" to their ethnicity and they wished to avoid persecution. Circumcision was a convenient emphasis over the cross of Christ, even though it nullified grace and the work of Christ became no effect unto them. The Jews of Galatia didn't have the same effect on Paul and he tells why in the next to last verse of the entire epistle (6:17):
From henceforth let no man trouble me: for I bear in my body the marks of the Lord Jesus.Persecution was a threat to professing Christians, so a motivating factor to pander (6:12). Paul, however, wasn't doing any handwringing over that possibility. Anything that they could have done to Paul, he had already experienced. His body was his biography and an anatomical masterpiece of perseverance. His kryptonite to Jewish intimidation was the scars of his personal suffering for Jesus. There was no pain that Paul had not already experienced. If he was going to fold under pressure, he would have already.
Paul's marks were actual marks. He could place an index finger on spots all over himself as the evidence of ugly wounds, each with an accompanying story. No one could trouble him.
On the other hand, men can be trouble to other men. You read this all over the Bible. It was a concern of Solomon about young men in the first chapter of Proverbs. Sinners would entice. They would be trouble. Something they were offering in the short term would look better than what God could give. It's never true, but it merited a serious warning from Solomon. The prospect of missing out on a fun time or not getting to look impressive to the appropriate people seem like enough trouble. Something far worse wouldn't be trouble for Paul.
The Galatian churches shouldn't be trouble for Paul either. They should have welcomed some marks to match his. If they were saved, they were, like Paul, crucified to the world. The cross of Christ was how they received justification before God. Their salvation came because of the Savior's suffering, because of His marks. Paul bore them too. Joining Him outside the camp. Pandering comes with the proposal of a better time in this world and glory received for a fair showing. It's not about the truth, but what will work on a momentary basis.
Doctrines and practices, once believed and lived in churches for over a thousand years, have disappeared like they never existed in a majority of churches today. They are difficult teachings, unacceptable to this world, although required by the next. Rather than preach and live those teachings, the majority of churches pander like the Judaizers did.
If the Judaizers really cared about circumcision, they would keep the rest of the law too. Circumcision was a convenience though. It would provide the most acceptance at the least possible cost.
For Paul, it was preaching only the cross of Christ. Today, like then, that message isn't good enough. The Judaizers were ancient advocates of contextualization, making the cross more appetizing to their context with a circumcision sugar-coat. A spoonful of circumcision might make the cross of Christ go down.
Churches today impress a different context, one obsessed with creature comfort. They have a Jesus who might slide down easier with the right mix of worldly and fleshly entertainment or amusement. Not only do you make it through unscathed, mark-free, but with a slightly Christianized version of almost everything the world has and does. That is trouble everywhere in Christianity today.
When even the Apostle Peter pandered to the James gang, as recounted in Galatians 2, Paul, the least of all apostles, confronted him to his face in harsh terms, not uncertain ones. Peter was becoming an accessory, even if he didn't accept the perversion himself. This is the case of a lot of professing Christian leaders today. They see the damage, but they don't want to hurt their numbers or coalitions, so they sign-off on the pandering that makes up such a big part of evangelical and fundamentalist churches today.