This is Sony’s decision. It is a material change to the product that was sold. It is not the same as a patch or a nerf. It has rendered the product unplayable. Yes, you can make the argument that it was listed on the page from the beginning that an account was required, but it is also the case that EULAs are actually not legally binding contracts. Sony has made a unilateral decision, and as a result it does not matter whether a person is finished with the game or not. This is a change to the actual contract, which was the purchase of a game to use in perpetuity for the length of time that it is available on steam. Sony has made this decision, customers don’t have to justify the reason that they don’t like the change. It is a change. They are counting on people letting it slide, because most of the time that is how businesses do business.
Also, you should really stop standing up for giant corporations. Sony doesn’t need your help. They have teams of lawyers whose job it is to argue with valve over whether they need to give refunds. They may also end up having to deal with class action lawsuits, and potential legal issues with 177 countries which may have completely different laws of consumer protection than the US. That is not your responsibility.
Besides, one of the pillars of capitalism is rational self-interest, and that goes both ways, not just in the business side. If you can get a refund for something because a company has made a bad decision about how they do their business, why do you care about whether it’s fair or not to the company? They sure don’t care about whether it’s fair to you. Are you a Sony lawyer? Are you the “be nice to big companies police”? Let Sony and Valve, and possibly the court system, worry about what their legal obligations are, and you worry about your personal decision of whether you are going to take advantage of your legal rights. Don’t start judging whether others should or shouldn’t do the same.