When you spend a certain amount of time thinking about certain issues and topics, you probably will end up with a vision of how you imagine and hope a possible future should look like.
You may be tempted to invest your time working towards such a vision. Of course you would, it's a great idea and you expect it'll be for the benefit of the people affected by the issue. For sure, everyone will listen to your idea, share your optimism, while adding constructive criticism, leaning towards an even better, improved proposal, thanks to the input you received through collaboration and dicussion. Maybe your idea turns out to be just okayish or there are too many variables that you didn't think of - sure, that can happen and it probably will in most cases.
In reality however, you will discover that there are people out there who lack such interest and vision. It's not that they've arrived at a different conclusion than you did, which on its own is a perfectly legitimate thing to do. No, instead of sharing their own ideas, they just want to stop you, after listening to your vision, if at all, They simply don't spend that much time thinking about the same things you do. They turn into adverseries and you may never find out why.
People tend to hold on to what they have, to avoid risks. Risks may have the consequence of losing what they already have. It's a natural reaction to fight those who dare to take risks.
If you think you're a person with ambitions and visions, chose your battles wisely. Investing too much time into a lost cause and fighting too many antagonists at once, is draining and it has the potential to rob you of your precious time. Time that might be invested better somewhere else, on fresh ideas.
Sometimes, it's better to let go. Even if hurts at first.
Edit #1: Revised a few sentences that were kind of hard to read.
Edit #2: Rephrased a few sentences that were bothering me.