Morally, yes. A patent needs to have utility for the quid quo pro to make any sense, it's the end products that have utility. Patenting necessary intermediates

Morally, yes. A patent needs to have utility for the quid quo pro to make any sense, it's the end products that have utility. Patenting necessary intermediates without disclosing the end products serves to retard innovation by everyone else without giving them the reward once the temporary monopoly expires. Legally, I would not be at all surprised to find out you were right.