Should I list my home with a Realtor who doesn't work on Sunday's? I wouldn't. It's like hiring a nurse who passes out at the site of needles. Clearly she's in the wrong profession. It sort of reminds me of the restaurant that doesn't serve wine or spirits. What's the point?
Real estate is a 7 day a week opportunity. I don't care if a real estate agent sells 50k homes a year, if he cannot service his sellers on a Sunday then he's subtracting from their opportunity to sell. Period. End of story.
If listing agent Don refuses to answer his phone on the Lord's Day, that's somewhat okay, but he should at the very least employ an answering service, have an assistant who will answer or even pass the opportunity to communicate to someone who is able and willing to work. The seller is entitled the opportunity to sell their home on busiest day of the week, this includes Sunday.
Here's another perspective...
Several times a year I work with relocation buyers (as do all agents) who fly in from other states. You can probably guess where this is going. They're only in for the weekend. If Stan The Man refuses to work real estate on the weekends his sellers will get passed on.
Just how long does it take to answer a call on a Sunday? 1 minute? Maybe 3? If you returned 3 calls, 2 text messages and 1 email you'd probably work less than 30 minutes FOR THE ENTIRE DAY. Is sidestepping your duties worth it? I can't schedule a showing when the agent doesn't answer his phone.
You aren't Chickila or REI. Your clients won't be impressed that you shutdown on Sunday so your employees can be with their families.