Yes! This, exactly! Why didn't we ever get to see Donald and Della clashing over their parenting styles? Why have we not seen a moment where Della feels insecure about the time she lost with her sons while Donald has always been there? Instead we get a very brief meeting in the S2 finale that is quickly glossed over so we get back to alien shenanigans. By S3, everything is back to normal. What happened?
We did get to see Della and Launchpad clash at least, but even this storyline feels unfinished. Worse still - it seems like it's a storyline that has a similar fate to Lena's, one that is completed off-screen. We see Launchpad worry that he's not good enough as an employee for Scrooge. Then, in S2, Della tells LP that he's a bad pilot because he crashes (by the end of the episode, she realizes that crashing safely is, in fact, a skill - one that she doesn't have). In S3, "Double-O-Duck," he specifically notes that he wishes he were smart so he could land a plane. But by the "Ragnarok" episode, he is able to land just fine. What happened?
According to the writer's Tumblr, Della's been teaching him off-screen. That doesn't seem consistent with her characterization in S3 thus far. She's only interacted with LP twice in S3, was aggressive towards him both times, and neither situation involved planes.
Instead of reading on Tumblr about stuff that happens off-screen, you know what would have been better? An episode where Della teaches him how to land successfully (which would be HUGE for Launchpad's character arc) and that gives him the confidence he needs before he leaves for St Canard. Likewise, it would allow Della to realize that she can be a pretty good teacher when she puts her mind to it. Both characters can walk away better people for having known each other.
But no. We need to have yet another pointless episode with the alien people. Who honestly never needed to exist in the first place. Ugh.