Possible meanings are 1) "for there were many tax collectors and sinful people who followed Jesus" or 2) "for Jesus had many disciples and they followed him."
The scribes and Pharisees asked this question to show they disapproved of Jesus' hospitality. This can be worded as a statement. AT: "He should not eat with sinners and tax collectors!" (See: [[rc://en/ta/man/translate/figs-rquestion]])