From what I’ve gathered with a cursory glance or two, people seem to dislike 1827 because they hate the “Tsuna is a blushing uke and Hibari is a typical seme” trope. As a queer girl, I can empathize with that frustration. However, I don’t this problem is specific to 1827; I think it is a general issue of homophobic misinterpretation of queer pairings. This trope is applied to so many M/M and F/F pairings; in fact, the seme/uke dichotomy is an inherent problem with yaoi. So I don’t really find the argument that 1827 is a “typical seme/uke ship” all that compelling because it really isn’t; it’s just that many (heterosexual fujoshi) make it out to be and misinterpret the dynamics of their relationship.
The reason I ship 1827 so fiercely is not because it’s so ~sexy~ to have Hibari “dominate” Tsuna. It’s because Hibari, who is a sadistic, independent, easily-angered, and fearful person, much like the unfettered cloud that strolls by at its own pace, was actually willing to fight alongside Tsuna even if he doesn’t usually stand with the rest of the Famiglia. There aren’t many people who pique Hibari’s interest; while he certainly acknowledges “carnivorous” fighters - such as Takeshi and Xanxus - he expresses his respect and admiration with a continuous desire to fight. We see this with his interactions with Reborn, Dino, Mukuro, and Tsuna. This is why when Tsuna is being trained by Hibari in the future arc, Hibari says: “you haven’t become like the you I know, the you who excites me as much as the infant [Reborn] does”. Like I said before: Hibari isn’t interested in most people and prefers to remain on the periphery, on the outside looking in.
And yet, despite that, Tsuna’s charm and overwhelming heart drew even him in. Hibari, of course, insists that he has no associations or ties to the Vongola Famiglia, and that he isn’t friends with any of them, including Tsuna, but we all know that underneath the surface Hibari is a precious and important person to Tsuna, someone Tsuna looks up to, respects, and relies on. The initial fear that Tsuna held for Hibari is still there to some degree, but lessens as the two of them fight in the same battles together, to the point that in the Inheritance Arc, Hibari tells Tsuna that “it is the sky that allows the clouds to move about freely”, and that one day he will “bite up the sky” itself. This means that he has not only acknowledged Tsuna, but that he has expressed a desire to fight with him. Coupling that with our knowledge on the nature of Hibari’s relationship with Tsuna in the future, and we see that their relationship develops to such a point that Tsuna’s initial blinding fear virtually disappears ten years later, and instead something close to resembling friendship settles in its place. In fact, I feel that Tsuna considers Hibari to be a precious friend (canonically speaking), even if Hibari denounces friendship and emotion.
Hibari is taller, older, and a little more muscular than Tsuna, but there’s no denying that their combat prowess and fighting ability are nearly equal. I’ve seen amazing art and read good fics that depict the equal footing of their relationship; it’s not as if all I see in the tags is Hibari dominating the shit out of Tsuna. I see fans who interpret the nature of their relationship correctly. In my perspective, the friendship that settles in place of the fear that Tsuna had and the disdain that Hibari showed transitions into something deeper. After all, Tsuna trusted Hibari - Hibari, not his best friend and right hand-man (Hayato) or his other best friend and other hand (Takeshi) - to train his younger self in the future and carry out the plan to attack the Millefiore. That level of trust speaks to me of a privacy and intimacy of a relationship deeper than burgeoning friendship. To me, it speaks volumes, especially when Hibari returned to Namimori in the future and went along with the plan.
This is a rough reasoning as to why I ship them. I could go on for ages but for now, I felt that this needed to be said, seeing as I’m a completely new member of the fandom. I didn’t even know that 1827 month was in January! Oh well, I’ll have to wait till next year. :D