Attention-seeking can come in different contexts. It's normal for humans to want to be seen and heard and known about, although "attention-seeking" seems too strong a term to describe that as, although, in a way, it is, if you get what I mean.
But actual attention-seeking behaviour as we know it is the unacceptable sort. I used to be an attention-seeker when I was a child, by becoming sulky and doing little things to get attention, such as hiding so that my family would come and find me, or dropping something on the floor on purpose, stuff like that.
I do crave attention in a way, but not the childish or narcissistic sort of attention-seeking behaviour. I'm just very expressive and I like people to know who I am. So with me I think it comes from being a social Aspie/ADHDer with extrovert traits. But there's nothing wrong with wanting to express oneself. It might stem from my teenage years when I was unpopular and lonely but really craved company and wanted to be known. I lacked attention too much from my peers back then, and so now I just want to be known, seen, heard, understood, etc.