Maybe it does sound a little blamey, yes, I don't know. The thing is I kinda understand XY too, XL's choice is irreversible, it's not something like choose power over love, or money over love, I mean death is death, no future, no plans, no nothing. Giving this, I don't see XY having an option at all, to be honest. In her words, that's worse than death. Living a long life with no one to keep her company, because the one she committed to is already dead. Yea, I belive she wouldn't have been able to keep on living without him, that's my take on SirBi's words. I don't actually blame anyone, that was just how fate was for them, wrong timing, I guess. If she would have committed herself to him, I belive she would have followed him în death, it runs în her family and that's not what XL wanted for her. On the other hand, if XL would have saved himself a life to live the rest of his life with XY, I highly doubt he could have ever been happy, not with all the memories of his fellow soldiers that lost their lifes on the battlefield. They both had their hands tied to be honest.
Edit altough IMO XY was more willing to take the risk and commit than XL ever was. The only reason why she didn't go along îs because XL didn't allow it. I pity XY more, because XL died, but she needs to keep on living yearning for him. Did his plan succeed? I don't belive so. He thought maybe that by killing the bugs her love for him will die too, but just as he was surprised to see the memories she kept în the mirror of him, he miscalculated the extent of her feelings too. Or who knows, maybe as she said în regards to tian er, as a lifetime pass, her feelings for Jing will eventually turn real too and thus XL's wish will become true.