My fiance (and her sister) always addresses her mom as Mother. She doesn’t do this with her dad only her mom. It always makes her sound stuck-up, and it drives me crazy.
My mother is ‘mother’. In all circumstances, at all times.
My mom is “Moo” (long story - involves my brother and really isn’t all that cute anymore after all these years so I’ll skip it) and my dad is, well was, “Daddy”.
At almost 42, I have to admit that I still call my parents “Mommy” and “Daddy.” And both of my sisters do it too. When we speak to each other, we refer to our parents that way too. When I’m talking about them, I call them “my mom” or “my dad.”
My sons’ 4-year old cousin has started calling her mother “Mother.” No one knows why, or where she got it from, but it sounds really weird coming from someone her age.
Ditto for me. I think it’s an Englishy thing. My mother calls her own mother “mother.” And she called her father “father.”
A 4-Her at my horse barn always calls her mother, “mother” and it sounds really weird. It is the only term she ever uses and she says it a lot and she seems like a really polite and sweet girl, but the constant use of “mother” makes her sound petulant. “Mother, please bring me the hoof pick.” “I’ll be done riding in 10 minutes mother.”
I don’t like the word mother when I think about it; too close to smother. ; )
Mother is, as noted above, the term denoting exasperation, from the teen years on. When I’m not annoyed at her, mine is “Mom,” “Marmar,” or “Der Liddle Marmar.” I’m 50. 
Dad is dad, unless I’m feeling particularly affectionate, at which point it is “Daddy,” or jocular: “Daddy-poo.”
I think folks are more likely to use Mother than Father because Priests are more widely known and addressed in most of society than Mothers Superior. Or at least that would be a guess.