I remember Blalock not being pleased at all with the trellium storyline, but I thought it was a great way to position her to be a Vulcan struggling with emotions - like Spock's duality, which was so intriguing.
I'm inclined to agree with Jolene in this matter. Fifty years ago, "they" seemed to be concerned that the alien Spock might be too "evil" looking and unrelatable, but the STAR TREK format demanded he be there every week. So to remedy that, they naturally made him half Human. Twenty years later, of course, none of that's a problem. Emboldened, Shatner presents audiences with Sybok who, quite simply, chose to be emotional. The implication there seems to be that he might've been manipulated by the god-creature the whole time. Spock repeatedly asserted that Sybok was a genius, perhaps his instability came with that, as it often seems to here on earth? To me, T'Pol's being compromised sort of negates her Sybokian emotionalism and simply presents her as a victim. I would've put a quick halt to that, myself if I came onboard as the new showrunner ...
I would argue that Vulcan civilisation at that time was "fallen" due to the lost of Surek's teachings. T'Pol was happy to escape the corrupt, hypocritical, chauvinist culture of Vulcan at that time, and may have felt that Earth culture had more integrity, even if it was primitive and irrational.
I did not care for the "corrupted" teachings angle to justify ENT's insistance on playing fast and loose with the Vulcans, to make it easy for its writers to write. "Oh! But it's so hard to write drama for people who have no emotions." Get out of Hollywood and go be a plumber, then. And when we DO get to see Surak's people living the "right" way, T'Pau's treatment of Archer & T'Pol doesn't coincide. Nor does Syran's for that matter ...