My Raleigh Competition GS is from the late 70's. It has Weinmain A124 concave rims that have a 14 mm inner width. This is intended for those that want to run 23 to 28 mm wide tires, possibly narrower. By having a presta valve, the rim is probably stronger than having a hole for a schrader.
I'm not even certain I could easily mount a tire on that rim easily if the valve were schrader as the width of the tire beads plus the width of the schrader and it's additional rubber to strengthen the tube are certainly using up quite a few of those 14 mm's.
At any rate, I've never seen a schrader drilling on those rims. So to me presta valves make sense.
Since road bikes went through the era of skinny tires and rims which then dictated presta valves, it is what will be standard for many years to come even though most road bikers now are running wider tires. It's a historical thing I believe, and most of us are happy with them.
Your disadvantages you share still seem to be more operator issues than issues with the design itself.