I don't think you can. The user base != the service, and not all users are equal.
When I look at the Parler situation, I think most likely poor management/decisions were the greatest contributing factor to their current predicament.
The management probably didn't think they had a hate-speech problem until it was too late. As such, they didn't have the systems in place to deal with it, and the systems they were going to put in place were going to be tempory (as highlighted by Apple's response to their app modernisation plan).
From any service, someone's presence at a political rally, followed by being present inside of the capitol building as a violent mob storms through while representatives are evacuated in fear of their lives, is a pretty good filter, regardless of them being Parler users, for "users who are probably either insurrectionists or journalists".
You can filter down from there, but even if you mistakenly think that fifty percent of Parler users just liked the idea of free speech platforms enough that they used a site frequented by the neo-nazis despite all that, it's likely that only the violent insurrectionists happened to be the ones in the crowd, and then in the capitol building, posting things to Parler as they went.
> I think most likely poor management/decisions were the greatest contributing factor to their current predicament
Like, having a panel of 5 human moderators "vote" on every piece of flagged content? As if that could even scale. It was never their intent to moderate in the first place, but rather to pull large segments of our political system into the very position we're now seeing -- namely, open conflict.
Honestly, there was no way for them to not know that, unless they never open their own site. Their site also had moderation structures in place - leftist opinions were removed fast. It was meant for right wing only.
When I look at the Parler situation, I think most likely poor management/decisions were the greatest contributing factor to their current predicament.
The management probably didn't think they had a hate-speech problem until it was too late. As such, they didn't have the systems in place to deal with it, and the systems they were going to put in place were going to be tempory (as highlighted by Apple's response to their app modernisation plan).