Yes I think you're absolutely right. It's probably the most dominant driver of all.
Though, the thing I love about having a diaper fetish is that it works on so many levels.
There's the humiliation part. Then there's the "animalistic" part (you love the smells, you love the way it feels). Then there's the "role play" part and the "I'm doing something BAD and I love it" part ("I'm 59 but I'm dressed as and acting like a naughty diaper-wearing toddler!") And the "helplessness / dominance" part, for anybody who is lucky enough to have someone else diaper them. And the plain old fetish part (being attracted to the diapers / plastic pants / sissy clothes / bottles / pacifiers / etc for just being what they are).
But most all of "the roads" lead back to humiliation. The idea that we love something that's taboo because only little kids do it, that we should have grown up and given this up when we were three but we still do it and love it, and that we secretly wish that everybody in the world knew.
For me, most all of the other aspects still lead back to the humiliation aspect. I love sissy clothes not only because they help me regress, but because of the excitement of thinking of the reactions others would have if they only knew. Same thing with all of the other "baby" items. And that's part of why I love my diaper pail. Is there anything more humiliating than the notion of you being caught in your diapers and then having that person discover your diaper pail, seeing just how many diapers you've used, seeing and smelling what a big toddler you are, and then laughing at you?
Anyway, yes, bingo. You're spot on with that observation!