Azzarello - The Final Judgement.

[Dr. Poison]

I'd say because Rucka actually had a good story, but someone at DC decided it wasn't what they wanted. (Hence why Simone wasn't allowed to use his designs for the gods).
Heinberg was... well wasn't that more of a mini-series more than anything? He wrote Who is Wonder Woman? as a mini and was out the door afterwards despite DC making it part of the main book. Plus it was illustrated by the Dodsons who are a huge draw as well.
And Piccoult; I suppose people jumped at those because she couldn't put a book out on time, so it looked like this would be the last WW book ever.

I wish Piccoult wouldn't have put out a single Wonder Woman story. it was a horribly boring follow-up to Heinberg's run.

[Lex Luthor]

Seeing how Themyscira and the Amazons are a big part of the story, I don't see how that would have worked.

tbh the most significant and interesting parts had very little to do with the amazons esp since they were turned into snakes for most of the run. he could have found a way im sure

[Silvanus]

So then why did 3 continuous runs(Rucka, Heinberg, & Piccoult) sell well?

Rucka's run didn't really sell all that well, but was often down in the 20's and 30's, until its numbers were bumped up by crossover, guest star or event issues.(He deserved to sell much better, but quality--as I see it--doesn't always correlate with sales. )Heinberg and Piccolut weren't around long enough to see their sales slip away as much as they might have.