Goes both ways though, just because people are loud in comments doesn't mean they're the majority. I'll see this come up on image sites or forums where something gets heavily upvoted but it's not "true futa" and such and so either one or two people say something or there's a big tirade. That's not even getting into the "balls vs no balls" hardliners you find.
Personally don't care too much, though I find having both's just werd for me so Tgirls are a preference.
No, being loudest doesn't neccessarilly mean anything either, but if more people express opinion A than opinion B, that's at least an indication that opinion A is more common, though it musn't be the case. I tried a vote at another forum one time, just to get the opinion of the silent people. The result were the same, the majority wanted futa and shemale to split into two different categories. There's a logic to that. If you like both, you don't have that much to loose on a split. At most, you'll have to type in two tags when you search for your futa and shemale porn, which is a minor inconvenience. But if you like one, but not the other, then getting the two mixed up can be rather annoying, for some even off putting. Kind of like looking for straight porn and suddenly finding yourself watching gay porn. Some people will not be bothered by that, but some will be very bothered. Especially since you can get pretty far into a game/story/clip before realizing that the futa is a shemale rather than a futa, or the other way around.