While there were some very bad actors with ill intents there doing really bad things - actually another good debate topic, the over whelming majority that were there were simple protestors. Voicing their political opinions. As we saw with the protests throughout the country, a few bad people can make a whole group look like savages.
There is video of Capitol police opening the doors and letting people in. Why should those who were let in be charged? They were let in by the Capitol Police.
Why were the people who were let out put on a gag order that they couldn't talk about their experience, those that did were arrested. Yet the government could keep directing its own narrative without any rebuttal.
We can keep going on and on with the unanswered questions, but I think you get the point.
So, In as far as your question, I would say that every single person, with the exception of the first mentioned group, is a political prisoner.