I assume that you are talking about in the galleries. If your shots get a lot of views, that probably means they have generated some interest and have some visual impact in terms of content and technique.
Some viewers I think are not sure whether they should make a comment at all, and others feel that they don't have the background/experience necessary to make a valuable or worthwhile comment.
Still others do not wish to point out lots of mistakes in a photo that some poster thought was good enough to put in their gallery.
Complicationg things further, for technical reasons what you see of your photos on your computer in terms of brightness, colour etc. may not be exactly the same as what other viewers see.
skieur