Ianto Jones hated Torchwood. He truly did. It gave him his first love, Lisa, and for the first time everything was perfect. But then it took her away, cruelly and slowly. A year. She suffered for a year because of Torchwood.
Then there was Jack. The impossible, perfect and broken man from the future. Trapped in a thankless job as cannon fodder for centuries, each death chipping away at his soul, forced to watch everyone he loved die and waste away as he persevered, waiting for the "Proper Kind of Doctor" to save him. Ianto hated Torchwood because just as it gave him something that really mattered it tore it away.
Jack had been dead for three days now and Ianto couldn't even sit with him and beg for him to wake up, as he so dearly wanted to because Gwen held vigil by Jack's side, chasing all others away. As if she had sole rights as his "favourite" or whatever she thought she was. She had Rhys but he apparently wasn't enough and the only thing Ianto could think as he turned his back on the scene, coffee deposited at her side was that Gwen was Torchwood's tool in keeping him broken.
Ianto hated Torchwood more than anything as he watched the CCTV footage of Jack running towards the little blue box, a joyous grin splitting his face. A single tear crawled down his cheek as he watched the only thing he had left to hold himself together running towards answers and eternity in the stars. Running away from Ianto.
Ianto hated Torchwood because it kept him alone in the dark with the broken souls for the former Torchwood staff, none of who retired or quit. They were all just like him looking for something, be it love or adventure of knowledge, finding it in Torchwood and have it ripped away by the same.
He hated Torchwood for breaking him, for making him this darkness. But, mostly, right now, he hated Jack. Hated Jack for leaving him when Jack knew better than anybody what Torchwood does to people. What Torchwood does to Ianto.