I'll admit I don't really understand the concept of a "realistic optimist" even though I'd wager that the odds of every optimist being unrealistic is low. I do have a bias towards pessimism being more realistic than optimism.
The optimists in my life kind of just say that stuff will work out in the end without evidence to support that claim. I assume it won't work out unless I can prove - or feel fairly confident, at minimum - it will (prior success, material evidence, etc). When the worst comes, I handle it because I saw it coming/prepared while the optimists sit in shock that it actually happened. When I suggest failure as the most likely outcome of a scenario (evidence-based, of course) and act under the assumption it will happen that way I'm called a pessimist as if that's an insult. I know one optimist in my life who consistently denies reality and substitutes it for her own peaches-and-cream one.
I definitely have a more cynical viewpoint than they do, which I think is more realistic. I know you probably don't agree, but I'd be curious to know why. Maybe my understanding of optimism is flawed. For instance, what's considered a positive outcome, if it's something that can always be in reach?