I think that’s right, with the ire coming from the perception of being cheated somehow. There’s a fair group of people who think anything other than changing the price or the product name is deceptive, and they’ll keep talking about it that way even if other people don’t see it as worse than a price increase.

The ire comes from the actual deception. Why do companies make products worse rather than bumping the price? It's not because they think that's what people prefer. It's because they hope that at least some buyers won't notice the change. People think it's deceptive because it is.