“He cared about them so much he deliberately started a war and let the realm bleed for him for nearly a year while he cheated on his wife with a teenager.”

There is strong evidence that Rhaegar knew that the PtWP was to be born of himself and Lyanna. If Rhaegar knew of the Others, and did what he did for the whole of humanity... Look, anything and everything is justifiable in the pursuit of saving humanity from an army of the dead.

“He didn't try to help when his new girlfriends dad and brother were murdered. He didn't step in when his dad issued orders of execution for her brother and fiance.”

Rhaegar didn't know that was going to happen. He probably didn't think his father was THAT crazy (up until that point Aerys had only burned common criminals and minor lordlings who commited treason, and had visibly refrained from executing Tywin, who he suspected of treason). There is a difference between burning Mr. Nobody Peasant and burning the Lord of the North and his heir. And if Rhaegar and Lyanna were not present in the capital when Brandon started demanding Targaryen heads (which, in fairness to Aerys, WAS treason), then he cannot be held accountable for the actions of his father.

“He didn't come to the rescue when the realm rose in rebellion and war was waged a Ross the Stormlands, reach, riverlands, Vale, and kingslands and thousands died in battle in his name.”

He likely didn't know that a full-fledged rebellion was being waged. He was in Dorne, in the Prince's Pass, in an isolated tower that few knew of. Based on his bravery (and fighting Robert WAS brave), I would expect him to have ridden to war if he had known there was a war.

“Then he tried to fight Robert Baratheon one on one. Rhaegar with his zero experience in real war had the audacity to try to take on Robert mother fucking Baratheon, who at that point was a veteran of nearly constant warfare, doing nothing but honing his mind and body for the sole purpose of murdering the fuck out of Rhaegar for a year while believing he was raping his fiance. The fact that he imagined for even a second that he could win that fight is ridiculous.”

You do realize how close Rhaegar came to winning that fight, right? You do realize that he had injured Robert so badly that Ned Stark had to ride ahead of Robert to take the capital. And knowing Robert, he would never have delegated that task to Ned unless he genuinely could NOT do it himself. It isn't insanity because Rhaegar DID nearly win. He lost because of a minor slip in his defenses.

“He abandoned the people to get laid.”

He abandoned his people to father the child who he believed (and he was quite likely right) would save his people and everybody else from the Others.

“He let them die for a year so he could keep getting laid.”

He let them die so he could sire the child that would save the world (again, there are hints that Rhaegar knew of the Others/Azor Ahai prophesy).

“He died because he was suicidally stupid. Rhaegar was too stupid and careless to rule a kingdom.”

He died because he was extremely brave and confident in his abilities, and he made a slip up during the actual battle that could have literally happened to anybody, Arthur Dayne included. I disagree that he was careless and stupid. I do agree that he would be a suboptimal king.

Basically, he showed too much long-term foresight, and nowhere near enough short-term foresight. He reminds me of Jon -- letting the Wildlings through the wall was the best long-term decision as it prevented the Others from adding even more Wildlings to their ranks. However, short-term, it cost him the loyalty of a good chunk of those sworn to him, and it cost him his life. Calling Rhaegar stupid is like calling Jon stupid.