But I like Delphine. And Esbern, and I've liked the Blades since Morrowind. Now yes, like everyone else, I do like Paarthanax, but sometimes I tend to lean more on the side of the Blades when it comes to the death-or-live decision on him.
The Blades are dragonslayers, it's what they are made for and what they originated from, so I see no reason why people think it is blasphemous for them to want to kill another dragon. And yeah, I know Paarthanax isn't just 'some other dragon', but I sort of think he deserves to be killed. Delphine may seem like she bosses you around, but she's just strong-willed and determined and I think she makes a perfect leader for the Blades - she gets [censored] done and she gets it done right. That's just how she is, and I think she's doing a good job finding the Dragonborn, helping him, and rebuilding the Blades in Skyrim.
Paarthanax committed many atrocities and then 'turned good', I understand that, and some see it as recompense. But it's akin to saying a cold-blooded murder who murdered over 1000 innocent people should be acquitted of all charges simply by bringing about the downfall of... let's say a Mexican Drug Cartel. "You helped take down a Cartel, you are acquitted of all 1000 murder charges, you're free to go sir."