There is a huge difference between "things aren't quite as nice as they have been in the past" and "the magic is gone." The latter term makes it sound as if Bedford Falls has descended into Potterville, and I don't see that at all. But many people who have been going to WDW since the 1970s have noticed that something has changed, and if so many people notice it, they all can't be wrong.
A corporation is, to some degree, an aggregation of its employees. I have noticed slippage there, and have a brother who was a CM, and who gave it up because of the way employees were treated. And I'm not talking about mean or abusive treatment. Instead, hours were cut so that employees were barely above the level of part-time workers. They couldn't earn a living doing what they were doing. Benefits were cut. College students were being brought in as temporary interns who were taking the places of more experienced, higher paid long-term employees. All of this made WDW a less and less attractive place to work. And when your work force is disgruntled, negative changes will be noticed, and many people here have noticed them. Does that make WDW "non-magical"? I doubt it. But it would be naive to suggest that disgruntled employees, fewer employees, and a cut-back in ride maintenance budgets aren't bleeding through. Back in the day, a kernel of spilled popcorn was swept up in 30 seconds. Not any more. Does that ruin the magic? No. But it is silly to say that these changes aren't noticeable. We all interpret them and react to them differently.
Once upon a time, it seemed as if the Theme Parks were loss leaders designed to draw you in to the "world of Disney" so that you would buy tickets to see their movies, buy their toys, shop at the Disney stores, stay at their hotels and immerse yourself in the entire Disney experience. And if that meant that they lost a bit of money on every guest who walked through the gates due to extraordinary overhead, so be it. Every fire hydrant was going to be perfect. Every automatronic figure was going to function perfectly. Every kernel of popcorn was going to be swept up, and the employee who did so was going to whistle a happy tune while he did it. Then, it seemed as if a change occurred whereby the parks had to be profitable, and one of the best ways to increase profit is to decrease overhead. Yes, I notice the decrease in overhead. If you have been going to WDW since 1972 like I have, it would be really hard not to. Is it disappointing to see that WDW is no longer orders of magnitude better than its closer competitors? Sure. But does that decline equate to Disney being no better than its closest competitor, or to a total loss of magic? Not by a long stretch. Just my $0.02.