Why is that a feature? ...interesting :) Our stoves here usually have some heat-based protection, where you have to hold the knob pressed in until a tiny rod heats up (usually 2, 3 seconds) and after that you can release it and the gas will stay on. Without power, you just need a ligher (or anything releasing a spark) to ignite the gas. Also, the default configuration for gas stoves is 3x gas cooktop + 1x electric, so most people are covered in both cases.

I've used the design you're describing with a heat-based valve, and it's definitely superior. I've never seen a cooktop with both gas and electric - is this redundancy in case one service or the other is interrupted?

I have no idea what the reasoning behind it was then, but it was a standard carried over from yugoslav times (usually 3 gas + 1 electric or 2+2) :) So yeah, could be redundancy...

https://i.imgur.com/rHDaZxm.png <- something like this was standard, also back in the time the colors were browner ( eg. https://i.imgur.com/RJkq5GK.png ) :)

The modern variants look more like this: https://i.imgur.com/iJvKQjy.png or with inductive heat instead of resistive: https://i.imgur.com/BOetXJz.png

I remember only one gas outage (some repair work done somewhere and they closed the valves) but there were quite a few power outages, where you had to use a lighter.