I have to agree, video's that include "body parts" and irrelevant conversation are annoying. I understand, in a club environment or any public place, getting voices in a video is unavoidable as is (most likely) the occasional head or other body part.
Hearing voices, other than an explanation of something to do with the layout, and/or seeing body parts in a "home shot video" is annoying and probably should be avoided. I know when I do a video I try to do one when it it quiet around the house so there are no noises other than that of the train. You will never see a body part in my video's as I am the only one in the room and behind the camera.
As for video's of trains going through tunnels goes (cab views) well, tunnels are apart of a layout and the idea of a cab view video is to show the layout, all of it including tunnels whether they contain scenery or not. With that being said, I try to at least paint the insides of my tunnels black so I can see how watching a "tunnel segment" where all you see is green foam or bare ply etc is a little disappointing.
For me though, I don't look at a video to be critical of the "video technique", I look at them to see the layout or the work being done on a layout. Sure, a no noise, no body part, crystal clear, properly lit video is always preferable; however, most of us are amateurs when it comes to videoing something and are simply doing our best to show others what is going on. In short, appreciate the effort and ignore the distractions