I'm more inclined to suggest that if Venat wasn't a pretty woman who shed tears when she wiped out her people, very few people would sympathise with her. If the Sundered were able to find a way to defy their fate, then it stands to reason that the much more powerful and influential Unsundered could have done the same thing. It wasn't that Venat had some grand plan that meant she was actually the most intelligent person in the entire universe and knew some secret that numerous other Stars were unable to deduce. It's that she deliberately took away the ability of her own people to successfully fight against a threat and then claimed credit for something that she, herself, wasn't even responsible for.

Even after the Sundering, it was Zodiark who served as the ward against the Final Days. It was Zodiark who bought time against Meteion, not Hydaelyn. Furthermore, the Sundered would not have succeeded in any meaningful capacity if not for the numerous forms of aid provided by stronger beings, including the Unsundered, Midgardsomr and Hydaelyn's 'blessing'.

Ultimately, she didn't even try to approach the Convocation despite Emet-Selch making it perfectly clear that even in cases were he was sceptical about something, he had a duty to investigate for the sake of the Star. As a former member of the Convocation herself, Venat was also a highly respected figure within her society - so the idea that nobody would give her the time of day is strange, especially when a previous quest established her ability to show others memories imprinted upon the land...

As for the whole 'suffering is needed' angle, that doesn't make much sense either - because, again, numerous other Stars endured suffering to various degrees. Yet not a single person could rise up against Meteion until the Scions showed up? I don't buy it - since Venat simply contributed to denying many others the opportunity to do as much simply because she decided to embrace her delusions of grandeur and style herself as a goddess for reasons that weren't even explained.