Ah, well programmers are not underpaid.
Desktop applications typically log more man hours, so a project can range from hundreds or thousands of manhours to hundreds of thousands. Something like an OS can be along the lines of hundreds of thousands. For example, Vista cost Microsoft 6 billion to develop. Generally its always at least thousands.
Something like a banking app, is probably on the smaller side, but it does also require excellent encryption protocols which can't be short changed.
I think part of the problem for UWP is some perceive it as "a mobile" app platform, rather than a desktop, console, tablet, notebook, and mobile platform. This goes for institutions, users and developers.
There are plenty of apps on iOS, and much of the code can be re-used substantially reducing any cost. But the developers, users and institutions need to start to get the idea, that these are not merely for mobile.
Thankfully MS is focused on this at build apparently. Bringing more desktop apps to UWP. They are also making full office uwp, putting edge in the store, and I just heard a rumour adobe might be coming on board with their suite.
With the introduction of LTE enabled devices via windows on arm - it should start to become clear to people that UWP, is for MS products generally, not merely phones. And with people carrying LTE enabled tablets and notebooks, those mobile focus applications - ones with calling, GPS, banking etc, may see more appeal in coming to the platform.