Oh, sure, they can have short-term conflicts. They have to have short-term conflicts. They're very different people, and neither of them is perfect, and they often screw up and do wrong by each other. But if Babs is into Dinah and Dinah doesn't reciprocate, that's not a short-term conflict. That's just a long-term Babs Is Fucked. Which makes no sense to me, Dinah as a negative force in Barbara's life like that. I mean, if they're basically sisters, that's cool - I am sort of physically incapable of perceiving them that way, but I have surgically implanted slash goggles, so obviously I don't speak for the majority - but what's relevant there is that they both see the relationship that way. Likewise, if they're secretly in love, that's cool (very), but again, it's important they both see each other that way, and it isn't just one pining angstily away for the other. That's what Sasha/Bruce is for.
That said, I'm with you on wanting to see the current tension played out - I'm fairly disappointed that we never got any real resolution on the wedding or the Sin thing. For something between four and eight years (given the vagaries of comic book time), they were the most important people in each other's lives. Now, suddenly, basically completely out of the blue, Ollie is supposed to be the most important person in Dinah's life and Babs is supposed to be able to dial it back correspondingly. That is not the kind of thing that goes smoothly. Which, actually, Bedard seemed to have a pretty good handle on, from the Babs side. I mean, the Sin thing was kind of weird, and the Manhunter stalking was hilariously immature, but both actually made perfect sense in the context of Babs and Dinah having no idea how to cope with or even recognize the shift in their friendship. So that would have been not only interesting to see play out, but also a really important acknowledgment of what these three characters are supposed to mean to each other and how they affect each other. Not having or exploring that conflict would be dishonest, IMO.
On the other hand, I'd nevertheless say Bedard made the right call basically doing an ignore-fix rather than continuing that, and just jumping Babs and Dinah back to Thelma & Louise for the series wrap; it's not like any of Dinah's handlers are going to take on that story, and Babs has been shoved back in the Gotham box and no one there gives a shit about anything that's happened to Babs since she took off the Batsuit, so leaving them in that rut would not have been acceptable. (Not to mention that thematically, ending BoP with Dinah and Babs at odds would make no sense. Bad enough that Barbara's growth arc got reset to zero; doing the same to the central relationship would have made it twice as obscene a betrayal of the series.)