I don't usually get involved in this sort of discussion but cannot resist.
We were out on Royall Satin last week and generally found everybody to be well behaved. We ran the engine (for about 10 minutes) to start the heating early every evening and then, because the boat interior was only about 5℃, again fired up the heating in the morning when we got up at around 6:30 but without starting the engine, this boat had voltmeters on both the domestic and engine batteries so I could check the battery state. This was actually the only week in about 26 years that we have ever used the heating in the morning.
To avoid running the engine in the morning we have showers in the evening so the water is always nice and hot, we only use the minimal amount of lighting and have never had a battery problem (mistake to say that, there is always a first time).
Now a little story: Some years ago we were moored at Womack (staithe) and during the evening about every hour the boat next door started his engine for at least half an hour, we thought "he must go to bed in a minute" but no. This continued until about 11pm, by which time we had been in bed for some time and I had had enough so I got up, dressed and knocked on his door, one of the 6 people eventually came to the door and when questioned said "we are trying to watch TV and the batteries keep dying", I should also point out that pretty much every light on the boat was also on. After a few words he did shut his engine down and, I guess, went to bed.
Some of the problem with a certain yard is that their new boats are all electric so battery power (if not on an electric point) has to be used for cooking with the subsequent necessity to generate electricity from the engine, still you pay for diesel whereas you don't for gas (or am I being cynical) and it is easier on the BSS. Which leads me on to say that I am not convinced by hybrid boats even if they are totally covered with solar panels, I cannot see that they are efficient and the generator is silent, it's still a diesel engine after all.