I think the suggestions made above are probably all part of the truth. Another factor is that people will visit one forum more than another. If there is a new thread in the town/city mapping section, I always give it a look, at which point the urge to suggest/comment arises. I don't tend to bother so much with the regional maps (and I'm yet to visit the board game mappers). The finished maps forum, however, I visit much less often, because there is less chance I'll find something that interests me there.
By the way, if getting responses is what you are after, post something that generates discussion (mine is the 10th reply to your initial thread just today; MCC's question about subterranean city maps also generated a lot of interest in a short space of time).
I think that it's a good thing, if you want people to comment, to insist on a certain aspect of the map by asking a question about it. Instead of saying '' comments and critics welcome'' say '' what do you think about my mountains ?''
For my 2 cents here, I am much more a fan of watching a map evolve from start to finish rather than just looking at the finished product. On those occasions that I do peruse the "finished maps" sub-forum, I am more likely to follow a link to the original WIP thread so that I can see how the poster got from a blank sheet of paper to the finished product. For me, it's a chance to learn something new (hopefully) that I can apply to my own work.
In terms of "first finished map" versus something like "fiftieth finished map," I think it starts to become a matter of repetition. For some, that "first finished map" is a milestone of sorts, even when it doesn't have a professional look to it. For those of us viewing that "first finished map" it is a chance to offer encouragement, constructive feedback, tips, advice, and suggestions. Eventually that "first finished map" becomes a "second finished map," then a "tenth finished map," and, as it is in your case, a "fiftieth finished map." Okay maybe not all of us are quite that prolific, but, hopefully, the point I'm trying to make is clear. By the time you get to a tenth, twentieth, or fiftieth finished map, the style and quality of the map, and more specifically, the cartographer, is usually pretty solid and, I'd be willing to bet, unlikely to change. At that point, there may not be much for the rest of us to offer in the way of comments other than "nice," "great job," "excellent work," and so on. As nice as it can be to hear those kind of comments, it can be a bit cumbersome in terms of postings. Fortunately there is that little "like" button that we can hit if we want to show our appreciation.
Now, I'll readily admit that I'm guilty of not hitting that button as often as I should. In my defense, I'm only recently back as an active member of the forum and haven't had a chance to peruse the "finished maps" sub-forum at any length. I have every intention of doing so as time between my job and working on my own map permits.
In any event, I wouldn't take a lack of comments on a finished map as a negative. It may very well be that we just don't know what else to say that you haven't already heard.
All of you are not posting enough! You can make it all better by going out there and commenting. It's a virtuous circle - the more comments you make, the more comments they are likely to generate!
Go forth and comment, my sisters and brothers!
I can't speak for anyone other than myself, but I have a teacher and helper mentality. I like to help people get "over the hump," so to speak, until they get to the point where they have enough expertise to start helping themselves. I am far more likely click on a thread that's asking for help than I am one that says, "Look what I did." I almost never click on threads in the Finished Maps forum unless someone's caught my attention and I want to see what they've done. When I do, I seldom reply because I usually only say something if I have actual information to add to a thread.
I'll admit that fully half of my replies to all threads don't even get posted because right before I click Post, I always ask myself, "Really, does anyone even care what I think?" Usually I wrongly answer myself, "No" and click Cancel.