I do not know if it was the original intention of the founders, but you can't ignore that the people who are/were funding it are influential far-right figures.
Ok, so to you, it seems obvious and accepted that Rebecca Mercer is far-right.
However, traditionally, the terms "far-right" and "far-left" have been reserved for people who believe violent government coup is a legitimate means to an end.
And lately, people have taken to calling more moderate conservatives "far-right" and "nazis" as a way to delegitimize their opinions, and make them sound beyond-the-pale.
Ideologically far right doesn't mean 'racists take over capitol hill'.
AOC could be considered fairly 'far left' she's not exactly a radical.
To the OP's point, I think Parler was trying to legit be an alternative where they didn't have Jack Dorsey in charge, but I'm doubtful if they were actually looking for the holocaust denying crowd.
I suggest probably their comfort zone would have been 'Fox News'.
I'm sorry if this comes across sounding harsh, as I don't know you at all, but your comment sounds like the opinion of someone in a lefty filter bubble.
Where I'm from, "far-left" and "far-right" means "people who think violence is a legitimate means to enact their ideology."
So that includes Nazis, the KKK, and communist revolutionaries. It does not include Rebecca Mercer or Breitbart.
Check out this data: [1]. Breitbart is only a smidge more conservative than Fox News, and Fox News is the #1 watched cable news channel in the country. That is called "mainstream." Presumably, the "far-right" would be "far" beyond the mainstream.
Are they though? Maybe I just lack some knowledge but it seems there's a trend where these definitions are shifting so that right become far right, and sometimes even people who would have been left are suddenly being called right.
That said I don't know much about these particular people.
They seem to be comfortably in the progressive group in terms on their politics, if not always their rhetorics which sometimes seems calculated to appeal to center or right wing voters. But you can pretty much completely disregard what anyone in politics says and just go by what they do.