Pilot Stolas is just a completely different character at this point.
Pilot and Show Alastor have at least some consistent qualities with each other and are both evil pieces of shit.
My two cents as someone who has never actually seen either pilot but has heard a decent amount about them is the reason a lot of people were more attached to these characters in the pilot is because of the quality of their characterization. As a result, people became intrigued and they grew in popularity. It feels like Viv acknowledges this, enjoys the attention those characters receive, and decides to more or less make them the main characters. But because they've morphed into her creator pets, she has to erase what she sees as flaws, not realizing that a lot of what people like was a result of those perceived "flaws". Especially because in many cases, those flaws related to the character being evil. And to give her the faintest bit of credit...sometimes you have to do that with your main character. To instantly take that credit away, one of the perks of setting your show in hell is that you can not only get away with having more flawed characters due to the setting, but your audience is more or less expecting those traits because the shows are set in hell.
Obviously this is an extreme example, but if you were writing a character like Superman and had him blackmailing people for sex, then yeah, the audience would turn on him and rightly point out he's a villain. Nobody wants to read about a character who is supposed to be a bastion of morality doing something that is blatantly bad. But a demon or assassin who is literally in hell? It's completely different context. When Darth Vader chokes a subordinate for questioning him, we can see him as a badass because he's the villain. If Han said "I have a bad feeling about this" to Luke's plan, and Luke responded by choking him out, it'd be entirely out of character and people would sour on him.
That isn't to say characters can't change. It's actually something that the audience tends to enjoy, seeing their flawed characters face conflict, which causes them to transform and change their ways. But you have to actually build up on it. With some shows, it takes multiple episodes, others an entire season. Hell, some shows it's even the entire premise. It's not something that just happens off screen with no explanation.
It'd be one thing if she said the pilot episodes weren't actually canon. I mean, sometimes shows change from pilot to syndication. There might be tonal shifts, or even a character or two disappearing/new people being introduced. But these changes are to tweak things that don't work. For example, in the Seinfeld pilot, Jerry makes a comment about how Kramer hasn't left the apartment for 10 years, and this was envisioned as being part of his character (IIRC, it's even a couple of episodes before you see him outside of the apartment) but they realized how limiting that would be, since he'd basically show up in apartment scenes and wouldn't have all these zany off screen friends and adventures to reference.
If people are vocal about enjoying certain traits/settings/whatever, you don't want to remove those ones. If people responded well to Kramer in the pilot episode because he was goofy and whimsical, the writers wouldn't make him a straight laced wallstreet snob. I think it's a problem with Viv/the tumblr writing audience she seems to base her work on. One of the reasons Mary/Gary stues are so often seen in fanfic is a certain crowd of writers/readers gets very critical if a character is flawed. Usually because of projection issues. I don't think anyone was specifically saying that with Viv's characters to force her to change them, but I think because her own writing style is so based on tumblr-esque fanfic, she naturally applied that logic to her popular characters once she decided they were the mains, because in her mind, that's just how main characters are supposed to be.
