I think a "vote" system may allow for ponderation or averaging of opinions. Rating could even be continuous scale as oppose to a discrete scale (like 3.25, for example), if several opinions are averaged.
The problem is that some votes matter way more than others. Even if there are hundred votes stating an aircraft is good, but there's one dissenting vote from an aerospace engineer who is familiar with the plane, I'd discard the hundred votes.
FDM quality is not about opinions, likes and dislikes it's objectively definable and measurable.
Except, we can't seem to agree who is able to understand enough aerodynamics to judge planes. Case in point - observe Simon (Bomber) consistently arguing that the relevant measure is time spent with JSBSim rather than understanding the math for instance.
I readily recognize Vincent's points as entirely valid and reasonable, and I suspect so would anyone who knows aerodynamics, but the people who create unrealistic FDMs and overrate them would not recognize the same points as reasonable (or they would make different planes in the first place), nor recognize why general physics understanding is really helpful in judging what a plane should do - so we end up with the classic situation that proving expertise to an expert is not needed because an expert recognizes it anyway, but proving expertise to a non-expert is close to impossible because the non-expert does not know enough to recognize an expert.
So, an open vote would lead to a meaningless 'like/dislike' statement, whereas a vote among an expert panel would leave the question of who qualifies to be part of the panel.