You can imagine the sort of comment the early mammals made while waiting for the comet to strike.
"I don't mind them being so big and stupid, but why do they have to eat all the fruit? There'll be none left when they've finished."
And the dinosaurs saying "When we've gone you can eat what you like. Until then, leaves and branches was good enough for my grandfther and it's good enough for me." (The dinosaurs are too stupid to put it so coherently, but hey that's artistic licence for you.) And of course they were bigger, if not faster, so it was difficult to shove them out of the way.
But these days not only do the dinosaurs eat all the fruit but they uproot all the trees and they don't give you space to plant any more. So not only will the next generation not have any fruit to eat but they wouldn't know what it was if you gave it them.