Why are the people who come late when Shabbos is 4pm also do so when it is at 8.
I wonder if those who come late are generally the people who always work late on Fridays. Since their work schedule changes with the seasons (meaning, in summer they work later on Fridays), it still makes sense. I also wonder if people with two working parents in the family also have more trouble coming on time.
My theory is that generally, people with two working parents have less time on Friday to do all the small details. I know that on Fridays that my husband is off (he works every other Friday), we are ready on time and my husband is at shul on time (although our shul davens a few minutes after candle lighting). Its the weeks where he works that there are often last minute things that need taking care of.