Chinese mentality?

About your concern, I think they are not disrespecting you, it’s just a trivial matter, I don’t think it’s important to raise a comment.
In a small island as Taiwan where I live, while some people think that ”外公外婆” and “爺爺奶奶” are interchangeable, other people think they are not interchangeable.
The disagreement may date back to mǐn nán huà (Taiwanese or Taiwan dialect); there’s only two words, “ā gong” refers to both father’s father and mother’s father, and “ā mā” refers to father’s mother and mother’s mother.
Because the official language in Taiwan is Chinese, and it's the only written language shared by many spoken languages. So only in situations we want to say it in a clear way or in legal documents we say(write) “祖父 ” , "祖母”, ”外祖父” , ”外祖母”; otherwise, “爺爺” and “奶奶” are just like “ā gong” and “ā mā” or "外公" and "外婆" or "公公" and "婆婆" are warm for listeners, and all the eight are commonly used here. As to whether it is father’s or mother’s? No one care!
Here, in Taiwan, most young couples do not like to live with their parents, because of generation gap. I know in U.S. you’re much more independent than us. There are many reasons that young couples don’t want to live with their parents, one of them is that they fear thir children might be spoiled by their 爺爺奶奶.
Oh, I’m an English learner, and my writing having grammar or syntax errors is unavoidable.
Oh, I got a reason, to be called 爺爺奶奶, let us feel much more warm than 外公外婆.