I think that Crowley was never once in his existence appreciated. His son betrayed him (though we don’t know the reason why they hated each other), they call him names behind his back, they hunt him down for not serving Lucifer and having his own will and plans, they don’t accept him as their king. See, none of the demons respected him, they were not loyal to him - they feared him, and in order to survive they obeyed. Crowley worked his way up from the salesman to the King of Hell, and yet nobody paid him respect. The sad thing is, they never even wanted him as their king. They didn’t notice he was kidnapped. They didn’t come to save him when he called, none of them. Abbadon was the only one to show up, her only intention to kill him and become Queen of Hell. I’m not trying to shove him in the role of a victim, I know what he is and what he’s done.
I just think that beside the desire for love in his human heart, he pursued acknowledgement. And it makes me sick at heart that he’s never received neither.