"What reason" could Jesus have for enjoying fellowship with those who sin? Why does He sit down, relax, and eat with "those who disregard" His very own commands (that is, the Old Testament)? When Jesus went to Matthew's for dinner, the people with whom He ate were not reformed sinners looking for holiness. They were still "known as sinners" committed to a sinful lifestyle (Mt 9:10). These people were sinners who wanted to meet Matthew's new Friend, Jesus. Thus, Jesus' reputation took a nose-dive with the faithful.
Churchgoers can give lip-service to conversion, but a lot of people would resent suddenly having a bunch of sinners in the next pew. Would the church potluck lose its regulars if a group of alcoholics and prostitutes began coming on a regular basis? Would those regulars turn against you if you were the person inviting these sinful newcomers to new life in Jesus?
As disciples of Jesus, we place a higher priority on reconciliation than on our own reputation. Conversion comes first. If gaining conversions creates conversations that harm us, then so be it. Jesus Himself said: "Woe to you when all speak well of you" (Lk 6:26). Therefore, it can be a good thing for us when people speak against us for following Jesus.
Be like Matthew. Invite sinners to meet Jesus. Cause heaven to rejoice (Lk 15:7), even if it makes your reputation suffer.