Hi Stupot.
In my eyes you have a lovely exposure of the sky & captured the glow from the the light beam well. Only problem is you have very little in the shot other than the light house to keep the viewer involved with the photograph.
A nicely balanced photograph leads your eye around the picture....thus the 1/3 ratio of shots advice, plus use of "lead in lines" in the shot to give you eye something to follow, or something interesting in the foreground to give you a starting point to move on from.
So for your shot I think this is why people are drawn straight to the lighthouse, then feel they have nothing else to look at......I think this is what SteveC was saying. How to improve is a hard one. On a different night you may have some amazing clouds to add more texture & colour variation to the sky. Maybe a full moon in shot. As for foreground, not sure what there is you can use , especially when light is low. Maybe move around the lighthouse to add something that leads your eye into the shot etc.
Apologies if I've just taught your Granny to suck eggs
, but I hope this opinion helps
