Selective breeding has allowed humans to transform wolves into Chihuahuas, an inedible wild grass called Teosinte into Corn (Maize), and many other drastic modifications. But those aren't "frankensteining", apparently. To paraphrase Stewart Brand, inserting the DNA to express a protein that a mammal cell normally does into a plant cell does not mean it will be furry.
I took 'frankensteining' to mean a rapid progression and skip over many states which would have been encountered via selective breeding.
To take your example, the wolf -> chihuahua would have been frankensteining had it been over the course of a singular or very small amount of generations.
It's still comparatively slow and safe, however. Even though we make some really weird alterations that way to suit our needs (which is well and good in and of itself, why shouldn't we?), the time spans are usually waaay longer than what i refer to as "frankensteining". It's not like you have a wolf, then a chihuahua, and in step 3, all wolves are suddenly chihuahuas. But that is effectively what we can do when we use more artificial methods.
