First I'm not even going to touch that Yeti thing. It was done wrong from the start, so it's a bad example.
Second, you're missing my point. You can have 100 guys going around changing lightbulbs, but when the wiring that provides the electricity to the lightbulbs if shorted because of age, you have a bigger more complex problem. My point is that as things age, (and invariably all the news stuff will not age as gracefully as the classic stuff ) "stuff" breaks down. ( "Stuff" that was put in 20 years ago was way more complex than "stuff" done 20 years before that). Even with the most loving of maintenance things will stop working and need significantly more attention than they may have need a couple of years before that. You can't expect Splash, with it's numerous updates and upgrades to over the last 20 years to need the same level of upkeep that it did when it was 2 years old.
Now if you think that that would be reasonable to shut the ride down routinely for a week or two every couple of months, or maybe for a day a week, you wind up with two things: unhappy guests, an excuse to defer larger refurbs. Yes, you may have some more animatronics that work, but you're really shortchanging yourself in the long run. It's an inefficient use of resources and wasteful. You wind up killing yourself trying to put out every spot fire, while ignoring towering inferno right in front of you. (I knew I could get a fire service reference in here, take that brothers at the firehouse)
First, the Yeti worked at the start. Worked well. So, no, it's not a bad example.....
And again, DL has attractions even older than WDW. And they have been able to maintain, and even preventively maintain, those rides and attractions over a longer period of time. WDW needs to look to their example and perhaps reconsider investing in said maintenance, perhaps even preventing the need for longer down time for rides and attractions.