As for why people shame the dub, it is mainly because of bad censoring choices which either changed the meaning of whole plot points (like changing Marik killing his father to “sending him to the Shadow Realm”) to bizarre changes that make you wanna face palm (like instead of Tristan/Honda saying he has to pee on the boat to Duellist Kingdom, he says, “In a few hours, the sun will rise!”) to character name changes. Since a lot of people deem the YGO dub “bad”, they tend scoff it off even more. Because of this, there is a pressure in the fandom to watch the sub since a lot of people see it is as the “true version” and closer to the manga.

To be honest, I’d be lying if I said these changes bothered me sometimes and I vote the subbed version to be the better version hands down, but I have a small soft spot for the dub since it is the first version of the show I watched outside of YGOTAS.  I admit, I normally only watch the dub unless it is is so bad it is cringe worthy (which, unfortunately, YGO falls into that category for me). When I watch the subbed version of anything, I have keep my eyes glued to the computer or tv screen in order to get all the info; this, as you can imagine, is draining and I tend to miss a lot of info on the first time viewing. I watch the dub majority of the time since I can watch it more leisurely and know what is happening a ton easier.  So I can see where you are coming from.