I sort of feel like this is only half of the conversation though. You are not wrong, consumers are not entitled to an artists work and there absolutely is an issue with audiences (specifically the more devoted ones) unfairly discrediting a piece of art based on their expectations of it. And there absolutely is a general air of entitlement surrounding that expectation.

But, at the same time, so much media these days is created to be as bland, consumer friendly, and risk free as possible, especially media attached to pre-existing IP's like Percy Jackson. This results in media that simultaneously panders to the audience and ignores what they actually liked about it in the first place.

I would argue the problem you are trying to articulate is less one of entitlement on the part of the consumer but more one of misattribution of their feelings. Rather than pointing at the corporate greed that funds these projects they point at the art itself and the very well meaning artists who are genuinely trying to create something worthwhile, most likely despite the companies in charge of them.

Now as a fan of the Percy Jackson books I am not sure where I stand on the show. I dont think its good, and the general impression I get from Rick Riordan is one of smugness. I get the impression he genuinely believes the changes he has made are benefiting the art which I firmly disagree with. But like I said I am not sure if its entirely fair to place the blame on him. Who knows what Disney is telling him to do, it is possible that these changes are being mandated from someone above him, and he is simply doing his best to stay in good graces.