Until form is no longer synonymous with function, design will eschew ornamentation.
Taste is subjective, but is there really a more beautiful building in the world than the Heydar Aliyev Center?
I don't know about you, but I'd certainly put the Taj Mahal ahead of that, as well as any number of gothic Cathedrals.
I prefer Sydney Opera's outside shape.
The wiki pictures of the inside of the Heydar Aliyev Center also look odd to horrible to me.
Architectural taste doesn't align with the taste of everyone else. Why should that be the case? Why shouldn't architects design buildings people enjoy?
In many fields (architecture, art, cooking all come to mind) there seems to be an outright resistance to doing things that people actually enjoy. My hypothesis is that practitioners in those fields have spent so much time studying them, they have become bored of the "normal" stuff which people actually enjoy. In an effort to satisfy themselves, they optimize for novelty, either not knowing or not caring that doing so is making their work something which can only really be appreciated by people as desperate for novelty and steeped in the field as they are.
With food at least it isn't so bad, because there are a ton of not pretentious restaurants you can go to enjoy. Nobody can force you to go to the pretentious restaurants run by chefs bored of normal food. But with architecture, a building is something everyone in that city is forced to experience, whether they like it or not. It would be nice if architects were therefore more mindful that they should try to appeal to a broad range of tastes, not just architecture nerds who are bored of what came before.
No one will care if you build 1000th replica of a nice building. It's just not interesting to anyone and actually becomes boring very fast. People may live in it but no one will come from afar to visit it because of its beauty. It will become another one in a row of the same.
If you build a striking, exceptional building, it can become a big success (like Gehry's in Bilbao which is a success story for the whole city), so people who commission buildings sometimes select for that.
And also there is a sizable group of people who actually enjoy interesting buildings, like people who enjoy haute couture or haute cuisine etc., so it's not like there is no market for that.