Why do angiosperms make up the majority of the plant species?

People make a big deal about the dinosaurs dying, but they forget that dinosaurs didn't eat the same food that mammals eat. When dinosaurs ruled the planet, most plants were gymnosperms ("naked seeds"). That means ferns and pines and evergreens. Mammals now rule the planet, and mammals eat flowering plants, which are angiosperms ("clothed seeds").

If you observe something, that is science. When you ask why, that is religion. People keep asking why, and that is why "Intelligent Design" keeps on keeping on.