fylum-qordata:
For those who don’t know, the Exquisite Beast is a series of drawings in which two artists take turns supplying a reiteration of the previous monster, “evolving” from its previous design. Each artist adds to or alters the original form.

Since then, the idea of evolving art has…
I am going to have to disagree with this. You have said that the biodiversity of today is because of the splitting of multiple lines of ancestry and while this is true, you seem to have disregarded the fact that all animals of today have a common ancestor.
And though it’s true that exquisite beast does not have thousands of species which would ordinarily evolve through cladogenesis, this is because it would be absolutely ridiculous to trace an entire planet’s ecosystem through hundreds of millions of years.
The point of exquisite beast was to trace a single species/organism throughout its various iterations, not to trace an ecosystem or a genus. Perhaps exquisite beast only tracks the anogenesis of this species, not the cladogenesis — but perhaps it does track cladogenesis. Perhaps it does simulate the splitting of a single species into multiple species but chooses to focus on a single side of that split, which was their intention to begin with.
You say that for something to evolve that drastically would take absurd amounts of time, well, this is true. But perhaps it did take absurd amounts of time — its creators never specified a time scale. Yes, it surely did take millions and millions of years. To go into as much detail as to how each generation looks compared to its predecessors would be ridiculous! They obviously only chose to represent its iterations at very large intervals of time — this point is moot.
You say that it is an oversimplification to have an animal grow fur because it became cold, yet you haven’t specified what they should have included instead. It is a simplification, yes, but it’s an accurate one — animals do grow fur when it gets cold. You want them to include why it got cold? Maybe they migrated — but then why did they migrate? Predators? Why did the predators get there?
What I’m saying is that everything is an oversimplification. You want them to make a food web, well, food webs are simplifications. You want them to invent an ecosystem, well, the word ecosystem itself is an oversimplification. Nature is complicated. Even naturalists and scientists have difficulty representing it in anything other than a gross oversimplification.
You lift up Yet Another Exquisite Beast Clone as being better for scientists and more logically minded people — yet it has none of your listed requirements either. It is oversimplified as well. It is unrealistic. It has leaps in time. Yet Another Exquisite Beast Clone is nice too, it’s fun, it’s interesting, yet it is fiction.
You say that Exquisite Beast is for artists. Well it is. It is for artists and writers and anyone who wants to read something interesting. That is called fiction, sir, and if you don’t want to read it, go read your Animal Encyclopedia or something.