Coasters having expiration dates?

Dragons could have very well had some design or manufacture flaws that required it’s early demise. It’s way too complicated to assume one thing or another, IMO.

 

Even if that were the case, Universal has already proven that they were willing to rebuild a signature steel coaster from scratch to maintain (if not pluss) the experience. There is nothing to say that they couldn't have done the same thing if they really wanted these coasters to live on... This situation is simple enough to pin it to the factors that are apparent--Universal and JK Rowling made the determination Dragons no longer had a place in The Wizarding World and the land was more valuable to be used for a different attraction. End of service life was an excuse to pull the plug despite the fact that they extended the service life of a comparable attraction in the same park without challenge less than two years earlier.

Oh, absolutely. There is no doubt JK Rowling 'aided' the decision making process.