I’ve noticed this trend in a lot of DC projects, or at least the animated ones. In the 90s when Batman: The Animated Series was airing, they skipped over Jason Todd and had Tim Drake as the second Robin, instead of the third. I read somewhere at the time DC wanted to promote the current Robin at the time, Tim Drake. Also in a special feature on the BTAS DVD set, Paul Dini and Bruce Timm talk about Jason and how that version of Tim was a mixture of both Jason and Tim, and the reason they couldn’t have him was because his death quoting “…which was a very strong story and one that we couldn’t do in our series.”
In the current DC Animated movies universe, or the New52 movies, both Jason and Tim seem to never exist. I know they want to promote Damian, but I can’t help but wonder, are we losing those connection that have been established for years by just erasing them?
Dick Grayson’s status will remain unmatched as he’s been around almost as long as Batman has, but I’d really like to see the other Robins acknowledged currently.
The animated Tim Drake essentially was post-Crisis Jason Todd under a different name. That’s actually kinda unfortunate for Tim Drake fans, if you think about it. (Granted, I’m not that big on Drake. He doesn’t really offer a counterpoint to Batman in the way that Dick, Carrie, Jason, and Damian do. He’s just too much like Bruce. It works when he’s teaming up with other people, though.)
Some writers don’t put them in the show because usually they want to push the robin that is currently there. But that is just for the shows and movies, and a lot of the times they don’t go along with the comics. In the comics Jason and Tim are still around, just not as robin anymore. It’s just them growing up. Damian is the current robin and writers will keep on pushing him to be until the next robin comes (Which I don’t think will be anytime soon).