Yeah I agree Raptor having some average showings outside the book doesn't do anything to stop him from appearing in Nightwing again.
If anything its a compliment as one person put it. Priest's Deathstroke could have used literally anyone else but he instead went with Raptor and gave him a role in one of the run's arcs. It shows that he's gained the attention of other writers.
Also bare in mind Seeley didn’t really want to share Raptor. He gave him a pretty definitive end, or at least tried. Comics being comics and all…
Raptor was fine. Better than Heartless for sure, but I never felt like the character was some missing piece to Dick's rogues gallery. I enjoyed the character a bit more early on but as time went on it felt like they tried to insert his character into Dick's history a bit too much. Him being there the moment when Dick's parents died, the implication he was in love with Dick's mom and they had a fling, and then I think the implied thread of him being Dick's biological father given that Dick was seemingly named after him. Both are named Richard. Stuff like that you see a lot in comics, but I tend to lose interest when connections get too involved. Another example is the old story where they were toying around with the idea that Bane was Bruce's half brother which eventually got cut off or something.
I still would like to see a Nigthwing story that is just a well crafted couple volumes where Dick goes up against a proper A List villain or villains. Be it Deathstroke, Joker, Bane, Riddler, or whoever. It is those kind of stories I feel reverberate more and Nightwing has very few of them across his solo stories I feel like. Deathstroke is one you think would be used more, but outside that one Renegade story which was kind of messy there isn't much.
The problem with Heartless is simply that he has mostly been background character sofar.
The thing with Deathstroke is that he is pretty successfull as a lead character in his own right. Since Flashpoint he had slightly more than 100 issues as a lead character, so he is usually not available to be the villain in the book of another character.
Even now after Dark Crisis this might have changed, I'm not sure if they can still really use him as a lead (on the other hand with how few characters DC has that can actually carry a book, they can't really afford to permanenty f*** one up).
I kind of get it but at the same time that connection to Dick's family is part of what made Raptor so impactful to Dick, especially the implications of the name. Though, yeah, finding out Dick was named after his mom's ex-boyfriend is...something.
I'm sceptical Taylor could craft a good story with an A-list villain, at least one that actually respects their pedigree. Have I mentioned before how he had Lex Luthor get fooled by a fake Lass of Truth?