More accurately, they were stating - not screaming - that there wasn't enough data yet. Data doesn't just pop up like a mushroom. Standards have to be established, info needs to be collected and vetted over a period that's going to be more than just one cycle of infections, and conclusions have to be made. But yeah let's prefer that they shoot first ask questions later.

They're dealing with a worldwide event in real time, and a virus that is a moving target (various strains), with various age groups that can and can't be vaccinated yet, and with a media and political knee-jerk reaction that means any declaration that might later need to be walked back would cause an even bigger uproar than the decision point where the CDC states masks are no longer required for the vaccinated.