Yeah, complains about stale too-warm air on the train and complains about staff airing the train during stops. This way you can't lose an argument either way.
It's not a complaint. It's a comment. That would never happen in the UK - so it's interesting to see a different approach in different countries. It's obviously higher risk - there's no door to stop someone jumping out the train. Whether it's better or worse is left to the reader to decide.
Similarly - I was once on a train in Italy which stopped at a station with platforms shorter than the train. We discovered this when we opened the door to find a big step down onto gravel. That's not something that happens in the UK.
The biggest difference of course is that the UK has much higher train doors. So an open door without a platform is very high off the ground. Perhaps that's why we have a different culture around it.
The UK also has the third-safest railway in Europe. Some of that will be the result of a safety culture which prevents staff from overriding a door lock.