But DC has rather strict laws about firearms, so it was rational to rely on a swarming approach and then try to exploit the gains from that tactic. While the attempt to take over the capitol failed insofar as Congress reconvened to finish the process of counting electoral college votes, and many of the participants have been or are about to be arrested, the far right has scored an outstanding propaganda victory (complete with photogenic martyrs) at little real cost. I would say 2021 has got off to a spectacular start for them.
https://mobile.twitter.com/JoshuaPotash/status/1347277542588...
If your aim is to stage a putsch for real, you wouldn't be bothered by some gun laws, you would've gone all in.
But you make a good point; perhaps the plotters over-relied on shock value and ended up half-assing it, or perhaps there was no more plan other than stirring up disorder and hoping to capitalize on an emergency situation.
I'm pessimistic about the long-term implications; the far right gave up on the idea of a political solution some time ago and the less far right is now about ready to join them.