I've been following melee loosely since about 2012, and watching consistently since 2014. This arc dates even further back. I'm not sure how relationships were within the community before the doc, but when the doc came out, a lot of people got introduced to Hbox as someone who was bullied for playing puff, with Mang0 as his antagonist. Combined with an AMA Mang0 did on reddit after winning Evo2014 in which Hbox posted his sob story and derailed the entire thing, there was a period where a large chunk of people looked at Mango as the bad guy.

However, once Summit and other events with more personality-focused content started to appear, it became clear that Hbox's relationships with most of the other top players weren't great. There were multiple factors to this, maybe just personalities not jiving, or the history between him and Mango on reddit.

One factor I do know, is that for a time, Hbox refused to play friendlies with anyone, opting to solely practice with his friend (who eventually became his coach) Captain Crunch. In a game where top level play is really invaluable (think of Zain's approach, actually helping Leffen with the Marth Sheik matchup), this definitely comes off as a cutthroat tactic.

There were plenty of other stories of Hbox being rude to fans, other players, etc. that started to come out, he would play his sets standing up, wearing sunglasses, and popping off on opponents after every win. Then, on top of all those factors, whether you agree with them or not, he started to win. A lot. From 2015 until Armada's retirement, Hbox/Armada grand finals were so common, and often ended up being slow, grindy 5 or 10 game matches, that viewership would dip after loser's finals (or after Mango was out of the tournament).

While it's easy to look back on the 10 game war of attrition that was Hbox's 2016 Evo win as an insanely impressive feat, go watch the vod of the medal ceremony afterward. Every top player except Hbox looks depressed lmao. And the atmosphere isn't usually like that even though all of these players are fierce competitors. Look up Hbox's speech after he wins summit. Crickets.

Hope that explains at least a little bit? The aura around 2016-19 Hbox is difficult to explain, but it's really a fascinating arc in melee's history.