Also, crocodilians have semi-erect limb posture but their metabolic rate is the same as other modern ectotherms. Moreover, some mammals don't have erect limb posture but are still endotherms. By the way, the three dinosaurs we used were the only three available. There was no horned dinosaurs that are preserved 3-dimensionally and not significantly altered by preparation. Personally, I don't see why it matters.
Dinosaurs are important biologically regardless of their metabolic rate.
This doesn't seem to be the opinion of the majority. The problem is that neither of these may be correct. For many of these creatures their daily life was probably more active than modern lions.