I'll volunteer another reason not to necessarily pay attention to my viewpoint: I'm pretty clearly one of those weaker mathematicians, so I have obvious motivations for seeing all of that side work as relevant.

I'll note that I think that there are people other than top researchers who have contributed enormously to the mathematical community through things other than research. For example, John Baez is listed amongst the mathematicians who influenced MathOverflow participants the most, in the same range as Fields medalists and historical greats, based on his expository contributions.

It is also worth noting that when one does read papers by the top named people, they often cite papers from people who clearly aren't in that top, using little constructions or generalizing bits or the like.

Yes, this is true and a good point. It can serve as a starting point for estimating effect sizes.