Such is the way of popular culture. You end up remembered for the stuff you'd rather forget.
Still, Marshall manages to give the character a tragic dimension. (Tragic, that is, beyond the fact that he's a 200-year-old African prince who wakes up in an LA full of blaxploitation stereotypes.)
The films were a reasonably successful cross between low-budget horror and blaxploitation, which was low-budget by definition. All the vampire tropes, plus big afros, a good-looking love interest, tall heels, a protagonist who wreaks vengeance on Whitey (particularly when Whitey's wearing a police uniform), and really great period dialogue. ("Hey, dude, that's a baaaaad cape!")
Of course it was produced by a white guy, Samuel Z. Arkoff, who claimed that "Arkoff" stood for "Action, Revolution, Killing, Oratory, Fantasy, Fornication," all of which he tried to include in each of his movies. (There are those who claim it can't be blaxploitation if it wasn't made by a white film company, a contention I don't propose to explore.)
Blacula kicked off a whole series of horror/blaxploitation crossover movies. Blaxploitation crosses pretty well with other genres. There's Cleopatra Jones (blaxploitation/Bond films), The Legend of Nigger Charley (blaxploitation/Westerns), and The Last Dragon (blaxploitation/martial arts).
But why did it stop there? I mean, we had all these talented black actors, and plenty of producers like Arkoff and Roger Corman, and a whole tradition of doing all-black versions of formerly white fare such as The Wizard of Oz and Hello, Dolly.
Why not blaxploitation war pictures? Foxy Brown, She-Wolf of the SS! I mean, I'd pay for that!
Blaxploitation/sword and sandal: Jive Sucka Caesar. (And come to think of it, if you remember that Maciste was supposed to be black, you could say that blaxploitation and sword-and-sandal were together from the beginning!)
And we've already got Afro Samurai, starring the voice of Samuel L. Jackson, so I guess that particular crossover has already been crossed.
There really haven't been any blaxploitation/science fiction crossovers that I know of (Brother from Another Planet doesn't count--- it was too sincere to be exploitative.) Fear of a Black Planet would be a pretty good title.
What genres have I missed? Feel free to exploit this topic!