The issue here is that they are charging more every year, and the overall quality of maintenance seems to be getting worse every year. As the guest, people are allowed to criticize WHATEVER they want and should not have to stand for being told to shut up and "enjoy themselves". That's stifling to free speech and only plays into corporate pockets. Especially since this is more than just broken lightbulbs, it can be anything that down-scales the experience. This also includes chipped paint everywhere, or broken effects/figures on rides, or trash scattered around. Or heck, even the closing or ruining of rides because they didn't perform proper maintenance when they had the chance.
It's also generally not just a single thing that makes the experience degrade. It's a multitude of things, all working together to make the experience a good deal less magical and more half-assed. A person might not notice a single bulb burned out if they didn't pay attention. But i think most everyone would notice if half or more of them were out. You'd probably be a bit irked, especially if this wasn't the only thing in need of help. Disney would gladly do anything they could to cut corners if they were allowed to and people just kept quiet. They're a corporation after profit first and foremost. If everyone really WAS happy with more than half the lightbulbs on Main Street burned out, most of the animatronics on the rides stationary, and other random things not working everywhere, Disney would just keep things broken and never fix a thing. This is happening right now and most people don't even care.
For all the money people spend lining the pockets of the Disney corporates, they should expect and receive the best experience possible. That's not a personal entitlement, i include EVERYONE in this statement. We've already seen what the indifferent attitude breeds, with all the maintenance issues and broken effects on rides. Given time, it will only get worse if people allow it to continue without speaking out. If Disney thought everyone thought everyone shared Jimmy Thick's ideals, they'd ruin the place. They're already gradually adapting people into not noticing cutbacks, while still charging people more than ever for the experience. If they do this gradually enough, and people still pay without complaining, they'll easily get by with this.
So after that wall of text, the real question is- how much would you actually take before it gets so cheaply maintained that it's impossible to enjoy yourself due to the distractions? The more people that just sit back and take it, the worse it's going to get. Attacking other people for complaining just feeds their greed and will make it worse and worse.
Should note that it doesn't ruin my vacation to see this stuff. It IS there and should indeed be talked about to give Disney a kick in the rear and get their act in gear. It's especially bad when i count the fact that i have only recently visited the park after having not gone since the mid-90's. Having not gone for so long really makes it all the more obvious all the stuff they've cut back on. While the frequent park goer may not have noticed the downgrades in maintenance due to how they've been introduced to them gradually, someone who hasn't had this done to them gradually (myself) can really see the effects clearly. Feel free to call me a whining complainer, but i'm just saying guests should have standards that were once in place. Especially since not caring will only make it worse.