Did the exact same thing not happen with Sera? Somebody is always going to get hurt when these decisions are made. You are right, Bioware simply can't please everyone, and if you're going to get complaints anyway, why not just go with what you want to do creatively?
For what it's worth, my heart goes out to you and to everyone else who wanted to romance Cassandra as a woman.
I dunno if it's exactly the same. There's certainly a lot less sexist and homophobic slurs being thrown around this time, and I think that's worth noting.
Again, I just wish they they had announced she was straight when they announced her as a LI, would have probably saved a lot of pain. When Sera was revealed as a lesbian she had just barely been revealed as a companion and a LI, so it's not like the same expectations where there, the reveal was immediate.
All I want is for Bioware to offer players like me an attractive androgynous/butch woman to romance as a woman, and I really wanted that to be Cassandra. Also as people have said there's the fact that she plays a much more major role to the game, and the DA series in general. I'm really not sure why Bioware has this trend of their "leading ladies" always being straight, I'd really like to know if it's intentional or just coincidental, because it's happened in literally all of their games up to this point.