Okay, others have pointed this out, but I want to reiterate it. The fact that you include the what-am-I-supposed-to-do,-apologize? part makes it look like you are confusing what people are doing. People don't hate dual wielding. They like dual wielding, as a concept. However, dual wielding, as it plays out based on the rules of the game, is mechanically underwhelming, underpowered, and generally disappointing. It makes people choose between what they want to do thematically (dual wield) and what they want to do mechanically (any other, more optimal, choice). That, at least for many people, is a design goal--if you're going to have differing fighting styles, and make characters choose between them in some relatively permanent way (such as feats and fighting style class features), then they should be relatively similar in power. About the only build in 5e which really is better off for having chosen dual wielding is a melee rogue, and that's just a rather dissatisfying selection space for such a broad thing.
The more attacks you get per round, the less benefit having one extra attack is. It's the law of diminishing returns. If you only get one attack (say, as a rogue), then that extra attack becomes really meaningful. A 20th level fighter with four attacks--they'd much rather increase the damage of those four attacks (such as with 2-handed weapons and the associated feats) than to get even-one-more just because.
Okay, that is both a cop-out and absolutely not fair to these theoretical people. They are talking about the mechanics of the build because that is usually the subject at hand. Again, and I really want to hear you acknowledge this point, people talk about dual wielding as suboptimal because they like the concept, and are disappointed in the mechanics presented.tl;dr: hate is perhaps not the best word, I wish people would care more about role-playing than roll-playing
Exactly.
These are all specifics of your campaign. Why would they effect the overall opinion of dual wielding, as presented on online forums?
And wouldn't it be a better situation for you not to be penalized mechanically for these backstory and tabletopping decisions?