This is how I've always felt about it too. All of Whedon's other shows had twists that made the audience hate entire seasons; there's no reason to believe Firefly would have escaped that pattern.

So instead of being sad it died early, we can be glad we can still imagine where it could have gone in the best case scenario. The vision in our minds will likely be better than what we would have got if it'd continued.

No need to worry about Jayne's inevitable face-heel turn, or whatever other terrible subplots could potentially have cropped up in later seasons like River developing explicit (rather than merely suggested) incestuous feelings for Simon, or Inara betraying the crew for a cure to her disease (before being welcomed back a season later), or Kaylee getting killed off out of nowhere because Whedon loves doing that to characters of her archetype, or YoSaffBridge becoming a core crew member after we learn her tragic backstory even though her awful personality hasn't changed at all.

And that's not even getting into what the network execs, who hated the show, would have done with their meddling. Things could have been so much worse. Fans should console themselves with the fact that the show at least died with its dignity intact, and we even got a movie that resolved a few of the major hanging threads.

No one talks about famous actor James Dean becoming an ultraconservative asshole, being closeted racist, or a serial abuser of women. He died before anything like that could happen. Firefly is the same way.

Something like this would have happened even if Joss Whedon wasn't revealed to be a scumbag. Adam Baldwin, the actor who played Jayne, went on to become a major mouthpiece for the alt-right and a mainstay of conservative Twitter. IIRC he's even the one who named GamerGate (not that the name required even a modicum of creativity).

If you want to know how the series would've been if it had stayed on, you can read the comics.

Yeah, but half a season?