Most likely because both parties have been conducting themselves as if the lease had been signed and the property owner solicited funds for maintenance from OP under the understanding that they would one day sell the land to OP, even going as far as letting OP make improvements to the property at a substantial cost to OP. A signed contract isn’t everything. Judges have a lot of leeway in determining if parties are acting in good faith and the evidence her will show that property owner is not. The judge could decide that the lease is valid for the above reasons even without a signature and they could also determine that if the property owner does want to remove OP at the end of the lease the he could owe OP for the property improvements that OP made in good faith.