I can only surmise it stems from an aversion to being hopped on.
…though such aversion is not universal.
It’s not a plural, it’s a diminutive, as in “Babs” for Barbara. More common in the UK, but just like -ie / -y in meaning. Just happens to look and sound like the plural.
Argh! Ninja’d by Thudlow! I wouldn’t have had a link, either. Oh well.
With my kids I’m the Dad. So that’s what they call me. You know, that or, uh, His Dadness, or uh, Dader, or El Daderino if they’re not into the whole brevity thing.
Nobody hops on the Dad, except the Grans and even they have to stop when they get big enough to cause damage. 
What did he call them after he joined the Masons?
But the Masons fixed that?
My father, throughout his entire life, called his father “puppa.” For years I thought it was an old country thing, but it turns out just to have been their thing.
I think Pop sounds more affectinate than Dad.
Because I’m not a soda.
Actually, now that I think about it, my four-year-old has taken to calling his mom “pop.”
He’s given all of us nicknames based on what we drink the most of; I’m “water.” His sister is “juice.”
Don Vito Corleone didn’t seem to mind (and nobody would dare call him any name he didn’t like!).
We called our father’s parents Grandma and Grandpa, and we called our mom’s parents Nana and Grandad. But my cousins called the latter pair Nana and Pop-Pop.
Mine used to call me dad, and mostly still do in actual conversation. One of my DILs asked me what she should call me, and I said “well, you can use my name, but if that’s uncomfortable for you, then you can call me “pops”, since you already have a ‘dad’.” So that’s sorta caught on in the FB venue. I really don’t care what they call me as long as it’s not disrespectful.
My grandfather was Pop. I’m Dad.
Weasel association anxiety disorder.
My dad is Pop to me and Poppop to my daughter.
I love being called Pops by my children and Pop-pop by theirs. The terms are used with great affection. Should I live long enough to have great grandchildren, maybe they will call me Pop-pop-pop. Probably not.
I grew up calling my father Papa, later Pa. I don’t think he’d love being called Pop, but he’d prefer it to Dad, I think. My father-in-law is Dad to his children, and Pop Pop to his grandchildren.
Well to be honest I have no personal experience firsthand as I called my dad daddy or dad but I never knew some dads hate it. I know my mom used to hate being called maam as it made her feel old,but as for pops I didnt know,i thought it was an affectionate term
#38 disagreeing posts. Why doesn’t our dad like it? Why do nearly all tv shows I remember as a kid have old men saying “don’t call me ‘Pop’”? Did this notion die a generation ago? I’m turning 50 this year.
I blame Dr. Seuss: It just gets wrong ideas into the heads of children.