The Previous Rebbe said:
The Rebbe Rashab writes in a letter that young married men rationalize their neglect to davven at length on Shabbos, saying that they want to positively influence their family members. He writes that this is a nonsensical claim.
Sefer HaSichos 5696, p. 115.
Suggested explanation: Of course it is necessary to influence one ‘s family, but that can be performed at other times. On Shabbos there is a special opportunity granted from above for Avodas HaTefillah, the service of prayer, so that should be the emphasis of the Chossid’s divine service on Shabbos. Since this task is very time-consuming, it is possible that no time will remain for influencing one ‘s family. However, this will constitute an indirect influence that will be even more powerful than a direct one.