That's an interesting question, tvad. I've never thought about that!
I suspect I somehow manage to ignore that aspect to some degree.
In any event, Fagan's delivery is still that of a "conventional" singer, delivering a "conventional" narrative. I don't perceive the aspect I referred to as "cartoonlsh" as present in the music of Becker and Fagan.
I'd never heard "Cousin Dupree" so I just listened to it. In this case, the lyrics are simply so blatantly sleazy that I don't see how the meaning could possibly be misconstrued.
My greatest issue with Steely Dan is the slickness of the music, beginning with Aja. Last night, I watched one of that series on the making of Classic albums that focused on Aja and it was illuminating to hear Fagan and Becker talk about, for example, their loser would-be hipster protagonist in "Deacon Blues". When they talked about this character, I felt much more able to relate to him, than when I listen to the song, itself. There's something about the degree to which the music has been fastidiously groomed that I find offputting or alienating. I much prefer the CTE, PL and KL albums.
And this is not because I don't like Jazz! I listen to more Jazz (50's to present) than anything else. Because of this and the fact that I've played guitar for many decades, I can really appreciate the high level of S. Dan's musicianship. But the Jazz elements in their recordings beginning with Aja sound very cheesy/lounge-y to me. They may be hip but they are so highly polished that they fail to engage me, emotionally. I dislike most prog and a lot of Fusion for the same reason. I'm afraid I'm rather myopic in this regard-- music that doesn't engage me emotionally doesn't interest me, period.
When it comes to S. Dan, the recordings I like, I really like and I listen to them regularly.
When it comes to explaining my musical preferences, it's really just guess-work. I can come up with reasons why I think I may prefer X yo Z, but I suspect a lot of this stuff really has very little to do with rationality. . .