This common reason for not coming to church shows two fundamental misunderstandings: 1) what is a Christian and 2) what is church. Help someone see that being a Christian means being part of a church.
People are not going to church as much as they used to. I could give you the statistics, but I don’t think that I need to because you’ve probably personally observed or experienced it yourself. You may have seen it with your own family members, your co-workers, your friends, in the conversations