Another voice for this critical feature. Your profile of customers has changed Hubspot, you need to recognize the fact that most companies run a mix of inbound and outbound marketing efforts, and you are helping nobody by restricting the ability to manually assign campaigns. We have no practical way to reliably measure the journey that offline contacts took if we can’t attach them to a campaign, which makes your reports useless.
This is not a nice-to-have, this is a market differentiation feature!