They are still more expensive than planes and there are fewer connections available, often not everyday of the week or only during certain times of year. But my biggest issue is that train companies don't work together internationally so that there are no "official" connecting trains. You basically need to book them separately and if one is late you are screwed…

Don't get me wrong, I like night trains and I use them, but there is still a long way to go to make them competitive against planes.

I'm generally against night trains. They only work well when you can get on just before your normal bedtime, sleep undistributed for 8 hours and then get off. That means you lose one great advantage of trains: all the places you can stop on the way.

Mean while night is always going to be low demand so it is the ideal time to shutdown one of your two tracks (assuming two tracks, which isn't always a given!) and do maintenance on it, thus ensuring your daytime trains are more reliable.