People said the exact same things as that when Origins was released, and how it wasn't BGII, and when Mass Effect 2 stripped away the RPG elements, and...
I'd also have to see some definitive info on who makes up the core fanbase, how many of them are disappointed, will that affect their purchases in the future, and data of that nature. Without that, it's simple speculation, or at best, anectdotal "I and some other people who make up the "core" fanbase didn't enjoy this, and therefor none of the core fanbase did".
Also, if the target demographic has shifted, when did that start? If it's been going on for a while, seeing as same-sex romance options aren't anything new, then what really makes up the "core" fanbase? Wouldn't that shifted demographic be the new core fanbase? Wouldn't that have started, or at least been in play if gay people are the target demographic as you say, since 2005 when Jade Empire came out?
To put it bluntly, what the post reads like, to me, is "I didn't get what I want, and now if I hope real hard, and wish upon star, BW will fail so hard!" Sorry you didn't get what you want, it happens to everyone in life at some point. Sometimes companies you like shift focus, sometimes people think they want something until they actually get it, and realize their memories don't quite match up to the product, and sometimes life just sucks. Either way, now you as a consumer get to make your choice. That said, the wishing real hard part doesn't really help, trust me, I've been trying it for years, and I'm still not massively rich, nor do I live on my own space station.