Ukraine making ridiculous demands means they’re not serious.
One might rather think that sacrificing and dying by the hundreds of thousands is an indication of "seriousness".
Demanding that an invader leave one's country and leave it intact is a demand that by no rational definition is "ridiculous."
The art of negotiating, by all the evidence, escaped the attention of the author of The Art of the Deal. One does not initiate the negotiation process by conceding everything. One does not begin, unsolicited, the process of negotiation on behalf of another by selling out the one represented.
At the beginning of my participation in this thread I concluded by saying: "But the real measure of his task is to get people to now believe that it is more desirable for Ukraine to win than for them to lose."
It is astonishing how potent the the Kool-Aid is once drunk.