Matthew was a tax collector, an occupation despised by many because it allowed for great profit at the expense of others through extortion.
As quoted in today's Magnificat, Saint John Chrysostom says of tax collectors:
The pursuit...was one full of all insolence and boldness, and a mode of gain whereof no fair account could be given, a shameless traffic, a robbery under cloak of law: yet nevertheless he who uttered the call was ashamed of none of these things.No, Jesus was not ashamed of Matthew. In fact, he called him to be one of his Twelve.
According to Francis Fernandez in his wonderful series In Conversation With God, Volume 7, despite the scorn given the position of tax collector:
It is an attractive post, however, due to its great potential for acquiring wealth. A tax collector seems to have enjoyed high social status, since Matthew made Jesus a great feast in his house; and there was a large company of tax collectors and others sitting at table with them. (Luke 5:29)So Matthew threw a party for Jesus and many other people, prompting the Pharisees to accuse Jesus of keeping company with sinners. Jesus, of course, responds that it is the sick who need a doctor and not the well.
I don't think Jesus went into that party, sat down and started telling all the guests why and how they were sinners. No, I think he sat down and loved them. I imagine he looked into their eyes and asked about their lives, their families. Had he been giving them a lecture about their failings, perhaps he would have gained the Pharisees' approval. He had only that day called Matthew to be an Apostle. And Scripture does not recount Jesus telling Matthew all the sins he would have to abandon in order to follow him. Matthew didn't need that. I imagine he looked into the eyes of Jesus and already knew.