Why does Harold Bloom use Satan as an archetype for the modern poet?

In The Anxiety of Influence Harold Bloom conducts an experiment in which he reads Milton's Paradise Lost as an allegory of the dilemma faced by the modern poet. In particular, he focuses on the character of Satan as representing an archetype of the modern poet. Why does Bloom do this? Well, he argues that strong poets, and he's thinking here of strong modern poets, can only truly read themselves, their own work. As such, their attitude, their response to the works of their predecessors is not that of literary critics and scholars. Just as Satan in Paradise Lost becomes weak on Mount Niphates when he reasons and compares, so the strong modern poet becomes weak when he or she seeks to treat their literary ancestors fairly and judiciously. Bloom refers to the following two statements of Satan which he regards as applicable to the birth of modern poetry:

"We know no time when we were not as now."
"To be weak is miserable, doing or suffering."

In the modern world, the poet as both human and poet finds himself falling from a previously exalted state, just like Satan himself. Having arrived in their respective kingdoms of darkness, they become separated from their former selves. Satan tries to make the best of a bad situation, rallying the fallen angels to make a heaven of Hell; and modern poets (one thinks of Eliot in The Waste Land) attempt to gather together the fractured remnants of a vanished high culture to create something new and shocking in the fallen world of modernity.
The modern poet, as separated from his cultural inheritance as much as Satan is from heaven, uses his skill to explore the fallen world, into which he has been thrown, to make a home for himself as Satan does with Hell. And just as Satan seeks to free himself from being shackled to an all-powerful God, so the strong modern poet consciously attempts to free himself from the oppressive burden of cultural heritage and influence.