I think if Marvel studios is putting forward Black Panther, Luke Cage, Dr Strange, and Ant-Man movies (not to mention other studios having thrown out three attempts at The Punisher), then there is nothing to say Green Arrow won't have a movie. DC at least is under the same corporate umbrella as a major studio, so the "getting it right" element, like with the Marvel Studios controlled movies thus far, is almost firmly in place.
And Cherokeesam: I don't think you really have a handle on what makes Ollie a hero, or why he became who he is. He didn't pull a Green Hornet, he was turned into Batman-lite after his origin was established, and that portion of his publishing life is now legendarily laughed at both on the pages and in the real world.
Why does he have a talent for archery? Why choose a bow to make on the island to hunt for food instead of something more mechanically simple like a spear, or less pursuit-heavy like a beartrap or snares? How does he end up so far away from shipping lanes and any island but an uninhabited one when he is supposedly off on his tod on a yacht (a plane crash is more plausible to be in the middle of nowhere when it happens)? What happens to his world while he's away? What turns him from playboy to urban hunter? Why does he only shoot to wound? (that one's easy to explain away). Why does he continue it when he gets home?
All questions that a good origin, or heck, even first superhero movie that has a main character that is not superpowered (ie they are not thrust into fighting crime because they accidentally got abilities to do more than normal humans and they're good people generally or suffer a tragedy, they chose it for other reasons) needs to answer.
Having a movie with a ten minute first act where a rich blonde guy is shooting arrows with uncanny skill at bobbing targets from a boat then falls overboard in a storm, wakes up on an island, and sets about getting off it is no journey at all, won't make the audience care about the character. And throwing in Dinah because "you have to have a love interest" serves only to detract from Ollie and his rise to herodom.
Now - if you have the Catwoman/Batman approach to Ollie and Dinah in the first instance, then it might just work. Dinah is a vigilante operating in Star City - but no one knows about her because she isn't looking to strike fear into anyone, or showboat. She just gets the job done, but enjoys it; enjoys the thrill. Ollie, back from the island and hardened from it, is starting out on whatever the driving evil of the plot is (got a new idea on that by the way). Goes in half-arsed on a gang that he believes has information, and gets his butt handed to him - rather brutally too. Pulled out of the fire by the mystery person who disappears before he sees them. Another night he returns, more determined that ever to get the information he needs. But before he drops in on them, his saviour appears behind him. It's Dinah, and she warns him not to go in again, and certainly not with the attitude his has. He mouths off, she verbally puts him down, which pisses him off. He tells her to bugger off, and she demonstrates how easily she can 'not bugger' off to prove how one person can beat him without trying, so what's a whole gang of nutjobs going to do to him a second time. Some rooftop flirtation once she's proven her point, a run or two more that softens his demeanour and starts to show him that he can enjoy the swash and buckle of it, and shows her that maybe people should know what she's doing so that less will fall prey to the corruption Ollie now sees and wants to fight.
Ta da...