13. Why Does Lord Shiva Prefer the Worship of the Shiva Lingam?
Lord Shiva is an ascetic god. He is Urdhvareta. The two times he shed his seed was for the welfare of three worlds (the birth of Kartikeya and Ayyappan). He has no home, no property. He has denounced all the worldly things and spends most of his time in meditation.
He drank Halahala to save this world. He even denounced his sexual life for the welfare of the world (per some stories). He killed many demons to free this world from evil. He considers all the living beings equal. He accepts those also who are abandoned by society. What he wants in return is just our devotion. Hindus indeed offer, many things to propitiate him, but those are optional.
He is so selfless that he does not even want people to worship his image. He wants his devotees to worship the image of Supreme Brahman, i.e., the Shiva lingam, as He is his creator.
Therefore, it does not seem logical that he would want his sexual organ to be worshiped by his devotees.