The credits are a reflection of the show having a film studio producing it. All Marvel movies also have long ass credits, and the credits always count as the runtime for the movies as well. So they're not doing anything different with the shows, people are just more pissed because of the episodic nature of it, and the episodes being relatively shorter. I do think the last three episodes will make up for it, though. I'm not sure they'll be 1 hour exactly, but I do think they'll be longer than the ones we've had so far, because we've officially reached the ''Marvel movie'' part of the show. I don't think they can keep stalling for much longer.
As for the credits for comic book creators, I don't think it's anything personal. As I noted in another thread, they also didn't credit Allan Heinberg and Jim Cheung even though the show CLEARLY took A LOT of inspiration from their Young Avengers run for episode 6, from the twins' personalities, to the specific powers they showcased, to the costume Billy was wearing. It's unfair, but it is what it is. It's probably just Marvel playing favorites for whatever reason.