You have to plan for the uncertainties. I've run automated (no supervision) systems on Windows with a graphical interface and now headless on Linux (just the terminal). Windows updates are the first things you disable through group policy, you wouldn't just be hoping Windows doesn't update. Of course for better stability you'd go with Linux. When you submit orders and they sit at the server for a while, you will need to check on them. It's not that you'd send them once and forget. You have to plan for every error you can imagine. Size and side errors are unlikely to occur if you verify everything you send and the code is solid to begin with. Then there are error correction functions which close positions in the end as a last resort. I've been travelling this week and only checked once per day on the status, it worked as expected. It helps that it's in the cloud and even for maintenance system resets, everything will (should) start up properly. This doesn't mean that there won't be edge case scenarios when new errors are introduced that I haven't planned for but those can affect a discretionary trader as well -- most traders aren't constantly eyeballing a screen.
I'm a professional software developer with over 20 years of experience. I build and test my systems like crazy. I don't even like going to get a cup of coffee or use the restroom while my gear is running without me. At worst some problem I never anticipated can arise (bad data, latency, insane volume, regime change, nuclear war, etc). At best I miss the chance to monitor my work in real time to see how they play out and learn.
I did not particularly enjoy that lifestyle. It's fine for 2, 3, 4 years but for close to a decade, it starts to get old. It sets significant limitations to what you can do in life. You most likely trade one time zone, so things like travelling can be accomplished in the off-hours. For me, if nuclear war breaks out, my main concern is not burning alive as my skin melts over my bone. Trading is important but in this case, secondary.
I agree with you. If your system does a couple of trades per day, it's ok to monitor via alerts, etc. If your system is very active, you will get in a jam in a split second.