I don't think so. I think the honest fans either forgiven or forgotten about the ending of ME3 by now. I was in full outrage mode about it when I first saw it. But the extended cut made it acceptable. And since then the indoctrination theory made it epic. And I also won't forget that the Citadel DLC was probably one of the best fan service expansions ever created. While Leviathan and Omega were pretty good as well.
It's similar to the people I see raving about a tv series ending differently than they had expected and going into full attack dog mode. That the ending "ruined everything". How could it? The ending is just an ending, it can't take back the dozens of hours of fun you had with the game / series before that. No, I think the blame entirely falls on EA / Bioware handling Pr like a 10 year old child. This jumping the ship is also like that, a proper captain at the helm wouldn't just abandon ship at the first sign of trouble, while there is still a chance to save it. Sure there is probably more money to be made on anthem, than dlcs for andromeda, but why can't they do both? If anything abandoning ME kills every last bit of faith people still had in bioware. So instead of flocking to anthem they'll probably just walk away. At least I'd like to think that. I'm certainly walking away, and I urge everyone to do the same, to let EA know how big a mistake they're making by putting all their bets on an MMO.
Sorry, I should have been more specific: From a narrative and creative standpoint, they put themselves in a tough corner with the way ME3 ended.
I agree with what you wrote and it all goes to it.
All told: This didn't need to be this way.