I am not saying it was great security. But they had loaded guns, and lead tends to change people's minds about doing dumb shit.
And let me be clear: I am not calling for mere protesters to be shot, but once it was obvious people were violently attacking police and trying to storm the Capitol it was time to repel the invaders. People hitting cops with flagpoles and sticks? Shoot them. Large groups beating police? Shoot them. I get the whole not wanting to escalate a protest idea, but trying to overtake the Capitol while the Presidential election is being certified is way beyond the usual throwing rocks and bottles at the local police type of stuff.
We saw what shooting just one insurgent at the threshold to the House Chamber did: it took the starch out of everyone else trying to get in there.