I believe it means he knew people who had developed bad habits of not attending church.
I do not think it means habit.
Luke 1:9 According to the
custom habit of the priests
Luke 2:42 When he was twelve years old, they went up to the festival, according to the
custom habit
Luke 22:39 And having gone forth, He went according to the
custom habit to the Mount of Olives, and the disciples also followed Him.
John 19:40 Taking Jesus' body, the two of them wrapped it, with the spices, in strips of linen. This was in accordance with Jewish burial
customs habits.
Acts of the Apostles 25:16 I told them that it is not the Roman
custom habit to hand over anyone before they have faced their accusers and have had an opportunity to defend themselves against the charges.
Acts of the Apostles 6:14 For we have heard him say that this Jesus of Nazareth will destroy this place and change the
customs habits Moses handed down to us.
Acts of the Apostles 16:21 by advocating
customs habits unlawful for us Romans to accept or practice.
I agree with you that it is the "habit" of some to miss meetings, but the word "custom" is obviously something different than a habit.
A custom is something a person does that is linked to tradition. Can you see it? I wonder why not.
Also, forsake is the wrong word for missed meetings. If I 'forsake" meetings it means I make the promise to myself that I will never go again. Do you think that is likely?