For an indie producer, to engage -- and remain for any serious length of time -- in development of a project is a testament of belief in the project. The producer works with no promise that the film will ever happen, and generally speaking will have nothing to show of their efforts unless the film actually gets made. If the film isn't made, the producer can't use the script to get them future work. If the film doesn't get made, the producer's reputation suffers -- even if they have improved the project with their involvement. Nonetheless, I find the development process invaluable for a number of reasons. One of the strongest benefits of development is that it reveals who you are truly collaborating with. Have you ever worked with a writer and director team and they think the script is perfect and you know it needs work -- and probably a lot of it? How do they respond to your notes? Do they recognize they can take the script further, or do they think you are just pushing them for pushing's sake? Do they think each new draft is perfect until you point out otherwise? Arguments are healthy, if they are used to bring things closer to the truth, and not just so that someone can feel they've won.
When supposed collaborators don't want notes, when they just want to go out with the script, or get angry that you have questions, or are confused, these are all good indications that you just are not going to get there. These are good indications that you are not working with people who want to make the best movie, but people who just want to be right. These are people who are telling you that they are not good collaborators. These people are using development to let you know that everything that comes next is not going to be an enjoyable process. They are asking you to evaluate your choice.