Or there's just a divide in terms of production quality that a lot of people can't get past. If you're unable to get into something, you're not going to watch it, and bad sound I know drives a lot of people away from some of the shows, and especially the "2nd tier" stuff.
I think the 'tier' word is a bit... too precise. There is a spectrum, with the best fan films being quite good, some being slightly less in one or two aspects... and even at that moment, it becomes a question of what is important to the viewer. And it's down from there, step by step, but in no clear order. I'm often surprised at what my in-person Trek friends think is 'great' and what they think is not worth watching. And which is which is not consistent. There are plenty of technically competent films released by Hollywood that I find unwatchable. Those of you here who are film professionals may have a clear way to classify everything, but my own experience says that that classification my not be in accord with the reaction of the non-film-pro viewers.
The single most difficult part of my website to work on in my Quick Picks. I try to list the best film from each of the better groups, allowing viewers to then go to the page or website of that group to find more. But the truth is, I don't like to remove a film. So I still have the pilot episode for Starship Exeter, although I think TTI is much better. And I haven't anything from "Hidden Frontier" although there are multiple comments directing readers to that series. I try to wait at least a month after release before making something a "Quick Pick" so it can be featured at least twice.
Some of the groups which I've picked a film or sub-series from are "second tier", yet I get plenty of positive comments about them, perhaps because they are less well known. I wish there was a simple way to signal folks, "You'll like this but not that." I can often predict that for in-person friends, but creating a system that would work in general has eluded me. That, plus the time factor, has left me begging other folks to write reviews and comments and then linking to those. To quote a cliche', one man's trash is another man's treasure.
Part of the issue here is, another cliche', "Where are the boundaries of Rome" ... or in this case, Trek. From your TOS purists to those who embrace JJTrek as the 'real deal' to those who include audio, novels, comics... some or all pro Trek and fan product, it all comes into play in judging.
There are people who love watching kids, and hunt through STR looking for the kid-done videos, and others that skip those.
Aside from a very few films I can't imagine anyone loving (save perhaps those who created them), and I classify as "Really, really bad stuff." (If I leave them out altogether I get notified about the fact they exist time and again, so that's not an option)... I can honestly state that I loathe telling others what they should like. In some cases, I express a negative opinion, but that doesn't mean somebody might love what I hate. XYZ produces films in which the female characters are humans who act and think like human males, not females. I detest that, but another person might love it.
When I used to listen to reviewers much more than I do, I didn't go to films they recommended, but films that sounded like I would like, even if they panned them.