One thing to remember is that the scholarly understanding of the founding fathers is much different from the cultural understanding. For whatever reason, a personality cult has developed around certain founding fathers, elevating them to almost legendary status and leaving others in the dust entirely. This has served to somewhat warp our impressions of the founders into unrealistic caricatures, some of which have inspired your question.

For example, you consider Washington a pragmatist. Certainly, American history-mythology about Washington's non-partisan nature and willingness to preserve the union through unpopular acts has contributed to this image, but remember this was the same man who held together a starving, freezing, losing, useless army through sheer force of will and belief in the righteousness of his cause. I'm fairly certain calling Washington a pragmatist in the presence of a Valley Forge veteran would get you a laugh in the face.

In the same vein, Jefferson is commonly viewed as the purest idealist of the founding fathers, yet he was someone who 3(!) times had to abandon his strict constitutional idealism to very pragmatically effectively govern.

So really, this whole question in the first place is somewhat inaccurate, though it is true that the more romanticized parts of the various founding fathers are their most obvious characteristics.

However, you have a point that we seem to remember the idealism of certain figures very clearly--Hamilton, Jefferson, Jay, Madison, Adams, Franklin, and others--while most of the other figures except the mighty General fall into the background. But the reason behind this is really quite simple: the others weren't very good symbols.

Pragmatism and effective governing aren't really characteristics that get most people excited. For example, Charles Coteworth Pinckney was a perfectly fine patriot and founding father. Sure, he took a little while to choose his side, and sure, he was old, rich, and probably cranky, but he was still as much a founding father as Adams. He certainly was a more effective leader and had a better military and civil crevice record than either Nathaniel Green or Patrick Henry. But Patrick Henry was young, attractive, and had the most memorable speech of the Revolution, and Nathaniel Green was young, attractive, and made brave, reckless decisions that somehow didn't get him killed. Both of those profiles sound a whole lot more exciting than "old British aristocrat turned patriot after they were already winning does perfectly good but unremarkable civil service work and rises to vice-presidential nominee."

There were 80-something signatures on the Constitution and Declaration. They included a lot of men like Charles Cotesworth Pinckney or John Livingston, perfectly good administrators and civil servants but otherwise rather unremarkable men. But a new Republic in need of legitimacy looks to others sorts of men for its symbols. It looks for the pragmatic, wise, handsome leader, and develops that image when the actual man turns out to be mortal just like anyone else. It looks to the principled, stubborn, irascible idealists who represent the various feeling and ideas behind this new democracy and foster that image when the actual men turn out to be just as fallible as anyone else. And they look to the young, passionate fireballs who can inspire future generations to do the same and further that appearance despite a lack of continued success from those same fireballs.