Microevolution is a fact - but what isn't a fact is that it results in gradual speciation events, rather than just minor change in species over time. Darwinian evolution is a different claim, and it assumes a much larger explanatory domain. Macroevolution presents some substantial problems for Darwinism. Of course, today we have theories in the post-Gould era that are elaborations on the 'punctuated equilibrium' concept. There are still some difficult philosophical challenges with evolution even in its most contemporary forms. The relative stasis within species across massive time spans is difficult to explain on a Darwinian account. Punctuated equilibrium was a theory that emerged as a way to tackle the problem of stasis, but you find that some of the prominent, tried-and-true Darwinists (like Dawkins) will gripe about PE because it is not nearly as implicitly atheistic as Darwinism is - and as opposed to being correct about change in species across time, Darwinists demonstrate their more pressing priority is their commitment to keeping God out of nature.