Not much of a comics reader but I feel so sorry for Frank Miller.
Year One is a great story. Maybe one of the greatest Batman stories ever (for whatever that's worth). And Catwoman being a hooker worked extremely well within that story. The problem was that after Year One was over and Batman's world returned to creators who didn't happen to be Frank Miller, it turned out to be a disastrous move for the character.
Actually, there are a few things in Dark Knight Returns and Year One that worked great for Miller when they only represented Miller's personal interpretation of the characters, that ended up really hurting the characters when the creators who followed Miller tried to incorporate the ideas into their own work.
But back to the hooker thing, while it seemed daring at the time back in the mid-1980s, the decades since have shown that this wasn't a Catwoman-only thing. Miller seems to see all women as prostitutes. Nearly every female character he has written or created since then has either been a victim or a prostitute, and often both. Soon after the Catwoman thing, he went back to Marvel and turned Stan Lee's sweet little Karen Page character into an actual crack whore, sucking dicks and starring in porn. Then of course came all the Sin City comics, where the bad women were all murderous, back-stabbing high society bitches and the "good" women were all murderous prostitutes selling themselves in Old Town. Dude has issues.
