At first I have to appologize, but I fell ill twice in the last three weeks and had much RL stuff to do as well.
The Polish government, like the other Allied governments, is in a bad situation. At first, they had demanded unconditional surrender for a long time. They want to destroy Germany, at least to a certain degree. To remove Germany as power is clear though. They want to part it and they had led their countries in doing so. They had bound their political carreers to that as well. A turn of 180° won't help them, especially if they had personal and/or national interests involved as well. If they could save their faces, they would accept peace, IF there is no national interest involved.
Churchill wanted to part Germany. He played like a player of the 19th century. And his plan had already failed in 1943 (Danube Federation
Donauföderation – Wikipedia). It was the plan to go back to 1866. However, Britain had lost many assets, including great parts of her fleet, in the meantime and the battle of Alta made it decisive for Churchill to make peace. He has played a game and lost. He had done so before and he would have no personal problems with that, at least none to prevent that peace. He was aware that FDR is not only an Ally.
Stalin is using his propaganda and uses the Germans to get money/technology/goods as reparations. In how far his turn is dangerous for him, remains to be seen, but the NKWD is still ruled by Beria. And purges happen in the USSR frrom time to time. So there won't be many to complain loudly.
FDR hates Germany too much and has bound his career too tight on the fight with the Axis, that he can't change now. He still thinks he has two possibilities. One can even work. The other, well,... if the alternative works, there might be some instant sunshine delivered to the USA.
Poland had ever been between a rock and a hard place. And after ww1 they had reclaimed independence, but PO both powerful neighbours. Even after they had an aggressive stand. There were more than one attempt to attack Germany with France. In 1941 they didn't sign the Atlantic Charta without the Caveat, that they could demand East Prussia and Silesia. Some quotes I made here were true for Polish politicians. They are OTL quotes, like Poland can't survive without Königsberg. The Polish population was in that days very catholic and nationalistic. To accept losing territory to Germany for peace would mean endangering their political carreers. Even more, if territory is lost the USSR and Poland became the puppet of one of them, or even both. Even the slightest hint by signing a reparatrions treaty might lead into the end of the carreer as well. That means, there is a lot of reasons, why they continue the war. Even if they have doubts or are even convinced, it will end in a catastrophe. The US made the same mistake in Vietnam, where they didn't stop the war, even though they knew they were losing, as they didn't want to be the first US politicians to lose a war.
