Does it rub you the wrong way when you tell someone about something you did and they say "Must be nice!"?

I happened to tell an acquaintance that I didn’t get up until 1:00 in the afternoon today. Actually, I hate it when that happens. Wrecks my whole day!
Her response was a vaguely sarcastic “Must be nice!”
My hackles rose. She’s pregnant. She doesn’t work. She sits around all day in her filthy house, doesn’t bother to clean it or look after her other two kids.
I responded “Yes, it is nice. I’m up at 6:00 every morning and I bust my ass all week long.”

Why do people say that??