They can't, not as long as "Indiana Jones" as a piece of intellectual property is owned by a multinational corporation that paid a lot of money to list it as an asset. The thinking there is "Why do we have this IP that could be making us money but isn't?"
That's why there are sequels to...
I liked the movie but I completely get what you are saying. I think it comes down to the difference that James Mangold brought to the project, as opposed to the more lighthearted touch Steven Spielberg brought to the other films.