It seems that they are using abstractions of the mind such as "bird" and "dinosaur" to write their narratives. These are categories that do not actually exist physically and so there is no organism called "bird" that defines the category. Instead the concept is like a Platonic Form of the mind and there is nothing wrong with that. Yet when it is said that "dinosaurs" were the ancestors of "birds" then it is important to note that the person writing that narrative is invoking categorical abstractions in the mind to get the mind to imagine forms. In invoking abstract concepts such as bird (which can mean anything from a humming bird to an ostrich) they are not actually tracing a lineage of organisms as empirical evidence of common descent, step by step. Often, they are not even thinking about such a sequence in a systematic and thorough going way and instead are imagining it. Then they tend to argue that critics have a lack of imagination. The irony of these claims about imagination is that they also claim that they are the representatives of the systematic thought typical to science.
They also tend to argue that critics are making an argument from personal incredulity.
The argument that incredible claims need incredibile evidence is sound, there is nothing personal about it.