I was with you till the last couple of paragraphs where I was like nope. Birds aren't just descendants of theropods. They are theropods. And even going by what you are saying, many of the animals that anyone in their right mind would unequivocally and definitely categorise as both dinosaurs and theropods (such as raptors, T-Rex etc) had hips that were definitely not like lizards, but very much resembling those of modern birds. So they shouldn't be called saurischians either, but according to you it would be scientific pedantry to call them dinosaurs as well, because it was really their distant ancestors that actually had lizard like hips. No, I'm pretty sure that's not the correct way to approach it.

I think your understanding of cladistics is a bit erroneous, and what I'm gathering is that the saurischian and ornithiscian distinction might be dated (or based on superficial similarities). But I have studied enough about the question of birds being dinosaurs or not (by "not", I mean if it's really pedantry to call them that), and I can tell you it's not pedantry in any way shape or form unless you want to bring into question the whole group of animals called dinosaurs in general. Birds aren't distant descendants of dinosaurs, nor is it misleading to call them dinosaurs. They are dinosaurs.