If lore said dragons had a hard time reproducing, needing places or items of great power because dragons souls were costly, then I would understand it, but dragons are the opposite of that, they are known for their virility, they can reproduce with just about anything, and the offspring will still have a lot of the Dragon powers, virility is one of the central themes of Dragons, so I don't see why creating a new Dragon would be so hard, the essence of Dragons want to multiply after all.
Dragons are beings of great power, but they are also beings of great virility, everything about their being says that reproduction is easy, considering that I don't see why making an artificial Dragon would be so hard, Dragon genetics are Hardy after all, and should instinctively be helping themselves keep existing.
While it is true that they can reproduce with just abut everything that will stand still long enough, the issue was reconstructing that template form pure magic, giving not just the form of a young dragon but an elder that has lived long enough to unlock some of the secrets of its blood and dreams. Having that copied by magic feels a little cheap.