You are making many assumptions and inferences. I do not understand why the situation was considered unusual when nothing was happening at all, just a room with a light on.
The lack of any observed activity or apparent changes as you indicated, means nothing. It is not reasonable to infer there is a problem based on their assumptions, without any concrete visualization, that something strange is going on. The people in the room were apparently not on the same schedule as the peepers; which is really a mute point as it shouldn't matter to the peepers.
Curious about nothing going on because you think there should be? Hmmm.....
The OP said they looked into the window and indicated they did not see any luggage so they were not just walking by and 'glancing' around.
They were actively looking onto someone else's room. They had to have stopped and looked into the room. This is strange.
If having a wider view means you can commit a crime, wow.
Now, noticing something that is actively going on should be paid attention to.
Too many people not minding their own business and interfering with unsolicited advice/actions, especially without cause. IMO.
Stay safe.