I have often heard people berate those who take jobs that would limits of stop church attendance, but I think that there is allowance for that. Should one not join the military or police force because they may have to work on Sunday? I doubt it.

Fellowship can be found anywhere, especially among members of ones own family, so I am not sure that they are missing a great deal at church.

And as sad as it may be, even among the church I attend, there are "cliques" or groupings of certain people. Whether they be ideological, familial, or just conflicts of personalities, they do exist. Maybe social groups are inevitable in any situation. And whenever you have groupings, there are going to be people who feel left out, some of there own free will, others who may be ignored, it is hard to say.

For these people I can see how they may not always attend. What I would recommend, if this trend truly worries you, is to simply ask someone why they don't always attend, you may be surprised by the answer. And as always, try to be tactful.