Every platform created for this reason that gains a large following does so specifically because it attracts people who recently got banned from some previous existing service for being terrible. See 8Chan post gamergate or Voat post-banning of r/fatpeoplehate. Not saying it's wrong to be pro-all-kinds-of-speech-allowed-on-platform-that-you-run, but those kinds of platforms usually only surge in popularity when a bunch of people get banned from a more mainstream platform where being a dick is against the rules.
Edit: don't want to make it sound like big tech companies like Twitter / FB and Amazon are "good" for doing this. They're only doing this because they feel pressure to do so. If the execs had a moral compass, they would treat every user the same, and ban people based on the same set of rules.
This does also mean that if it doesn’t die right now, eventually it will when the funders get tired of it.
The site was, for sure, intended originally as a right wing twitter. While they probably don't want extremists, per se, they have made absolutely no attempt to moderate legitimately violent rhetoric (c.f. the Lin Wood threat last week to have Pence executed, which seems extremely frightening in retrospect).
You can see some collected horror shows via aggregation like https://twitter.com/RWParlerWatch and https://www.reddit.com/r/ParlerWatch/
It is Daily Stormer or 8kun? No, not yet. But it's really, really bad there.
although MeWe had quickly attracted racists and actual nazis too, though.
It wasn't supposed to be like this. If it was just a bunch of right wingers hanging out and complaining, akin to the left-wingers you find on /r/politics or whatever, then no one would care.
But right wing grievance shifted over the Trump years into explicitly violent and insurrectionist rhetoric and imagery. And as of Wednesday that's no longer a theoretical threat.
Have Parler done anything specific to attract extremists, other than taking a hard stance on free speech? Just going by their splash page, and values page, I don't see anything that indicates they have.
The fact that it's user base may be overwhelmingly "dregs" seems to just be a function of the lack of free speech in mainstream platforms.