Here is a video essay on blockbuster music.
I would suggest to spend the time to watch it. If you really want the summary it is:
The Hollywood norm has always been creative unoriginality in music scoring. Often by copying the style of other movies and playing it safe.
It is possible that the references being copied in recent movies have a smaller gamut of music than in the past, but the major problem of forgettable music in modern blockbusters is not lack of originality, or risk.
The main thing that has changed is that music is now made in a computer. For good practical reasons: it is much cheaper and flexible to adapt to a movie in production, while it is still being cut. The problem is that computers have not been good at simulating instruments that stand on their own to do melody. Or at least it is not easy to do.
The boring music of modern blockbusters is due to the lack of subtlety in the choices that led to its production, which result in little focus in melody. Solo flutes are not the norm, drums beats are. And they are not very memorable.
While it is probably a combination of digital music affecting the movie making process and a shift towards de-emphasising music, it seems to me like a lost opportunity to make great popular art.
An easy accusation would be that music is yet another thing the creators are not putting their soul into. But I think the person scoring a movie might actually be very into it. To me it is more interesting whether they would have chosen their career path if they had grown listening to the work they are producing.
I think the problem is that the movie making process treats the public as mindless consumers who will be offended by more refined choices. While it is true that not all viewers will grasp and appreciate subtleties in a movie, this is not a reason to remove them from the movie. It is not a good reason to make a movie targetted at the lowerst denomicator. And it commits the sin of not leading by example - how are people supposed to be exposed to more complicated subjects and discover if they appreciate them? Is the only way to increase the depth of the movie to increase its complexity?
To me this sort of behaviour is a denouncement of responsibility. Irresponsibility and the accusation of elitism (the other defence of the bored/uninsprired creator), reminds me of news reporters accusing educators appearing in the news of any misinformation the news has spread. They say their job is entertainment and making money, not education. The defence of irresponsibility is to deny responsibility. I think it is a problem if the creator and the public think the creator has no responsibility.
Interestingly, the video above is a response to the following video.
Both are good, but I prefer the one that prefers function over form. That is what I would aspire to create if I was 15 years old and considering my career.