What does 2 Corinthians 11:7 mean?

It's not just sarcastically labelled "super-apostles" that Paul is concerned about (2 Corinthians 11:5). He's also bothered that the Corinthians themselves seem to be swayed by accusations against Paul. These included complaints that he was not impressive as a speaker and he experienced too much suffering. Focusing on appearances, instead of truth, they assume a divine messenger would be impressive and worldly.

Now Paul seems to answer another charge: He refused to take money from the Corinthians while serving them as a representative of Christ. He asks sarcastically if he sinned when he humbled himself in this. In truth, he did this in order to lift them up as children of God through their faith in Christ.

Paul had the right to ask them to support him financially while he was working with them. However, he never wanted any confusion about his motives to interfere with anyone trusting in Christ. He explained all of this in an earlier letter to them (1 Corinthians 9:4–18). Instead of taking money from them, Paul chose to work with his hands as a tent-maker. Scholars suggest this might be something to which Paul's opponents pointed as specific evidence that he was not truly an apostle. For ancient philosophers and traveling orators, manual labor was the last possible option for supporting oneself. In fact, it was a sign the speaker was not good enough to attract supporters. Perhaps Paul's accusers said that a genuine apostle of Jesus would not need to work with his hands as Paul did. These false teachers very likely accepted all the money the Corinthians would give to them.

Paul's comment shows that his refusal to take money from them continued to be a point of contention, despite his explanation. Some of them may simply have had a hard time respecting a teacher who was also a common laborer.