People don't know what you do and don't know is false information, nor is it other people's job to educate you when you can easily do that yourself. This misinformation & it's ilk have been posted so many times by so many people over the years; people engage with this type of misinformation to explain that their false info ends in hostility & ship wars. People had enough.
After 12 years of fighting bad-faith disinformation like this, folks no longer have the patience to explain things on the off chance the people (you) don't realize you're spreading misinformation. Cause 90% people posting this kind of disinformation over the past 12 years do so purposely do so due to their racism & trying to uplift their ship and they contribute to the mess of racism in the fandom. The choice to go with WA isn't some little-known thing. It's frabic of the show. It's assumed to be common knowledge.
Cause it's very easy to interview by showrunners, producers, writers and actors who explain what the story about ships/narrative choices to find this common knowledge. The setup of the show with Candice Patton as the leading lady and main love interest from the pilot is also very self-explanatory in showing that the information you posted wasn't right. Cause if it were your info was right, then Danielle would've been the leading lady/love interest. Nevermind the comics' main pairing of Westallen & Caitlin not being a part of the Flash comics. Again, easy info to google and just think about. People don't know you, how and why you posted, so people are going to assume that when you post disinformation about a very basic part of the show, it's just another bad-faith disinformation post meant to prop up your ship like the rest of the bad-faith disinfomation. Which why there was such a wide negative response.
Given that you here and in other comments you keep referring to wanting someone to explain everything, a PM where someone explained it etc, I'm sorry but that is just not it. Stop trusting info from strangers online and do your own research and find out the truth yourself. A quick Google search. Gain some general knowledge about the show and fandom, and then you will have a basic to know when things you read from others is true or not.
No one said you shouldn't ship SB. You assume that upset at misinformation equals folks telling you who to ship? Sure, people who replied don't ship the same ship as you, but saying "X info is wrong/lie about how the series was made & written" isn't saying you're wrong to ship your show
I've said all I'm going to say on this subject. Enjoy your ship. I still recommend learning a bit about the show and fandom from credible sources other than word of mouth to prevent mistakes like this, and you can understand why the fandom reacts the way it does. History doesn't go away cause your unaware of it.