Dad, I'm reading a lot of self-pity here. This is Izzy's coparenting situation, not yours.
Izzybell already said that she does reach out to him routinely and that she looks for his input. If he won't give it, she has no way to do anything but make the decisions on her own. Furthermore it's unreasonable to ask someone who's getting "go ■■■■ yourself" from a co-parent to respond with "maybe you'd like more custodial time". Attempting to coparent with a nominal adult who has to be coaxed and jollied into behaving with an adult is a losing game for everyone, most of all the kids.
Her ex didn't show up at the open house; that's his fault, not hers. He's an adult. She is not responsible for his emotions. He didn't take the child to camp as he was supposed to: it doesn't matter what he might have wanted; he had a responsibility, he blew it, and he also refused to communicate like a grownup about it. If what he wants is more time with his child, it's his responsibility to communicate with the mom, try to work something out like an adult, and if she's refusing unreasonably, go to court in the least disruptive and egotistical way possible. Because in the end this is about the kid, not him, and not the mom.
You don't know why their custodial situation is what it is. You're also assuming that she's got a standard-minimum arrangement and that she fought for it, and has not been willing to share more childrearing.
When dads walk away because they "fought and lost", the problem isn't that they lost. The problem is their own egotism. A dad who's worried about whether or not someone else has awarded him "full parent" is not actually thinking about being a parent: he's thinking about his own standing, his own ego and pride. He's not got his kids at the front of his mind. A dad who has got those things front of his mind will start thinking right away of how to make the most of his time with the kids, how to stay in their lives, how to mend things as necessary with the ex in order to be a more involved parent. And he will not be looking to start fights with the mom over custody again, either: he will try to work with, because that harmony is good for the kids. He will also take a long view, understanding that fatherhood is not for 18 years but for the rest of his children's life.
Judges are not usually stupid, and they see thousands of families. They can see when a dad is really more concerned about himself and his own self-image than he is about his kids, even when he's swearing up and down that he's really there for the kids. And no, they don't generally want to give custody to people who are like that. They know that all too often those parents don't really want the everyday scutwork of parenting, and will fob it off on someone else as soon as they can while making excuses and claiming all the credit they can. That's why, when California ran its mandatory 50-50 custody experiment, they found that within two years the kids were actually being cared for at mom's 80-85% of the time: she was the one who'd actually do it, and most of the dads didn't really want to be troubled. The problem then was that the mom was behaving as the custodial parent but not getting appropriate child support for the kids.
Maybe the big difference, when you went back to the judge, was that the judge could see that your thinking had shifted away from some of that radical egotism. Because you're right, it's not mom v. dad, it's supposed to be about parenting together after divorce.
Helplessness, incidentally, is normal in parenting. You will not have much control over anything. You don't control your school district. You don't control your kids' friendships once they get past a certain age. You don't control the other parent, grandparents, stepparents, etc. You don't control your employer's willingness to give you time off when there's a snow day called at 6 am and you've already taken off four mornings in the last two weeks for snow days. You don't control laws regarding child safety. You have only limited control over your child's health, mental and physical. Parenting is not so much for people who need to feel in total control of situations. Parenting is about rolling with what's there and doing the best you can with it.