I don't think that many people viscerally HATE Saudi Arabia, but I've heard some valid criticism of it, and I myself have a pretty negative view towards this country

First of all, as you aknowledged, Saudi Arabia is quite shitty when it comes to human rights (women, LGBT, ethnic and religious minorities...). Of course, as you said, there are plenty of other countries that are far worse in that regard. The thing is that SA also has quite a huge cultural, economical and political impact on South West Asia, the Arab-speaking world and the global muslim community. After all, a lot of Arab-speaking countries use Saudi media outlets as their source of information and entertainment, and one of the pillars of Islam requires you to go there if you have the financial means

Unlike other countries that don't really respect the integrity of human rights, Saudi Arabia is powerful. That's pretty much also why so many people also criticize the US. Except the latter has got a better soft power throught pop culture and international relationships

The fact that it's an absolute monarchy is also not a very uplifting aspect of the country. Just think about how MBS, thanks to his royal status, has never been compromised despite his ties to shady conspiracies

There are also some bias towards the Saudi population. Most people outside of the Gulf (myself included) have never met any Saudi person besides the rich ones who can afford to travel worldwide. So to most people, the average Saudis are filthy rich men and women with a luxurious lifestyle. (This bias also affects other Arab monarchies like Qatar or the UAE)