Gale Hawthorne just wanted to save everybody from the games and having to keep living like that.
And it cost him the one person he wanted to live that better life with.
In my opinion, Peeta only ever cared about saving Katniss, he was single minded in this. He never really thought about the bigger picture, about fighting back, not like Gale did. Not until he gave that motivation speech to Katniss while they were hiding out at Tigress’s. A speech that should have been Gales, since he was always the one to say they should fight back, that she should fight back, always putting that spark in her, even when she didn’t realize it at first, a spark that turned into a fire when she needed it. He loved her and wanted to protect her and keep her safe, but never tried to hold her back from the fight, was always right there beside her, knowing how strong she was, but still there if she needed him.
He was a real hero! The bomb thing was 100% Coin’s fault but he still blamed himself, just as he did for not getting more people out when 12 was bombed. And I cry cuz he knew walking into that room that she would blame him too, knew that she would would never be able to forgive him, he knew he had already lost her, and he didn’t even fight her on it, because he felt guilty for not keeping Prim safe like he promised. Even though he was not the one that put that bomb near her, not the one that put her in the middle of a war zone, but he will still carry that guilt, and the loss of Katniss, with him forever.