I was aware that the Genesis block's reward was unspendable, and that there was no UTXO for it in the UTXO Set. I thought that this was due to the Genesis block being hardcoded and the actual synchronization beginning with block #1. I have heard people in the past referring to the unspendability of the reward as a quirk or bug. Midmagic mentions that it's a hardcoded exception that made the Genesis Block coinbase unspendable.
Can someone elaborate in detail what makes Genesis block coinbase unspendable?