And the whole idea of a wind shell is something lightweight that repels most of the wind (and bugs!) while being quite breathable (far more so than a rain jacket) and a suitable outer layer for temps in the 40s and 50s. Adding waterproofing would destroy its purpose.
It's not the point to have a wind shell. The wind shell is just a means to an end - that end being to have, with modification, a jacket that is waterproof, ultralight/minimalist, durable (unlike Frogg Toggs), and still affordable.
The list of waterproof jackets on Sierra Trading Post is intriguing, and yes, some of them are very affordable, but I noticed they don't list the weights. I did look up the weight of one of them on another site (the most expensive one that was still <= my example price point of $60 [not saying this is my
price point, just that it's the example I gave in my first post]), and it was over 11 ounces (size medium). Seems excessive. Some of them might be better; I'd just have to take some more time with my online research.
That, or buck up and find the time to make my own.