There is no real excuse for creating bad movies. There are methods that can be used to emulate what a movie will become and correct issues with actor selection, staging, and scripts before the first frame is shot or before the first animated cell is drawn. They likely aren’t used because of an excessive focus on meeting deadlines and not enough focus on assuring quality of the result. This doesn’t just exist in films but with every product category ranging from cars to cell phones.
With digital emulation, we can create a reasonable facsimile of virtually anything be it product, building, or movie and as most have found out, doing so results in a far better, far cheaper, product creation process. This is because mistakes are caught early and timelines and quality can be better assured. Why we haven’t taken these steps more aggressively is likely because folks would rather avoid bad news than they would seek it out to correct the related problems.
Good news is the industry is likely going to figure this out, bad news is it won’t fix the movies coming out this weekend