It may be their right to pursue profits within the bounds of the law but that doesn't mean their actions along the way aren't distasteful.
"If you simply find the treatment of warehouse workers distasteful don't buy anything online"
Just because someone or something's actions are within the letter of the law doesn't mean they are exempt from criticism.
I don't have a strong opinion on the matter. If someone were to do a good job regulating them and make the situation better I'd approve. If someone were to do a bad job and make things worse I'd disapprove.
Whether regulation should stop YT from doing this is a legitimate question. Nothing else will prevent it. Observe that the government telling a private company what they must host on their platform is potentially more dangerous than the government telling a private company to take down a piece of content (neither of these are happening here but if we entertain the notion of regulating YT then these are to be considered).
Monopolies are bad, mmmkay?
They're struggling to even exercise basic human rights (freedom of movement, opinion, peaceful association, speech, etc, etc. There is probably a right for healthcare self-determination slipped in to the Universal Deceleration of Human Rights too it seems like the sort of thing they'd slip in). There is room to argue about whether the UDoHR applies here, but it is very notable that the anti-vaxers have nearly no power to have a quite reasonable interpretation stick.
Their opinions just don't matter. They appear to be on the verge of being confined to their homes while being widely condemned and socially ostracised. They are likely to be fired. Which is why it is so concerning that systematic oppression is being bought in to deal with them - this is Google crossing scary lines that didn't need to be crossed.