Yes, Severian is not a particularly good person, but does that make this a bad series of books? I don't think Wolfe is trying to present him as good, which would be hard to swallow. This is written entirely from Severian's viewpoint, not Wolfe's.
In the sequel-ish series, the Long Sun books, the protagonist _is_ a very good person, and he's a marked contrast to Severian.
And yet we’re made to swallow the fact that he’s an exceptionally good person, an amazing leader whome people follow with no afterthought, and the Chosen One who brings the era of the New Sun.
Are we? Wolfe has stated in interviews that Severian is not supposed to be seen as a good person, but rather a deeply flawed one.
> an amazing leader whome people follow with no afterthought
Severian only starts to draw a following once he becomes autarch, and then people aren’t following him as much as the office (or the effects of the office). Elsewhere, it is Severian who tags along with various people he meets.
> the Chosen One who brings the era of the New Sun.
Did you go on to read The Urth of the New Sun? I won’t spoil it here for others, but that book does reveal that Severian’s “chosenness” and “saving of the planet” isn’t ultimately all it was cracked up to be.
As for lack of character growth, it is strange that you list Dorcas an example, because IMHO her gradual development over books 1–3 (with the coda in book 4) is a poignant aspect of the work.
And incidentally, novels where a protagonist tours a world full of odd characters, and the author does not particularly develop these characters or even the protagonist, is a well-established literary genre that goes back many centuries (the picaresque).
Doesn't matter what he said in interviews. The third book is full to the brim with with thin hints or outright "we knew you were special, so we were searching for you high and low".
> Severian only starts to draw a following once he becomes autarch
Re-read the entire attack on Baldanders' castle. "The people naturally follow me" and all that.
> Did you go on to read The Urth of the New Sun?
I didn't and after the Book of the New Sun I frankly don't want to touch anything by Wolfe :)
> a well-established literary genre that goes back many centuries (the picaresque).
"picaresque: relating to an episodic style of fiction dealing with the adventures of a rough and dishonest but appealing hero."
The main problem is that Severian is anything but appealing.