If macroevolution is so patently obvious and true, surely you can explain the evidence to me.
And please, don't tell me Piltdown Man.
What, you don't accept that the skull of a modern human attached to the jaw of an orangutan (with its teeth filed down to look human) is evidence for macroevolution? Ha.
IME folks who accept microevolution but deny macroevolution usually don't understand the difference between the two. It's not because they're stupid (most of the evolution boosters in this thread don't know more about evolution than those criticizing it), it's simply because evolution runs contrary to their beliefs. For whatever reason, they can accept the irrefutable evidence for microevolution (e.g. the evolution of antibiotic resistant strains of bacteria), but can't accept the inferences used to explain macroevolution.
The bottom line is this: the only difference between micro- and macroevolution is in our minds. There is no objective truth (with a little 't' - this is science) separating the two. Microevolution is usually described as evolution on a short enough and small enough scale that human science can irrefutably observe it. Macroevolution on the other hand takes a long time and the magnitude of change is so great that human science can't easily, irrefutably observe it. However, these differences are nothing more than semantics first used by biologists for the sake of convenience, but since exploited by evolution deniers to maintain what they think is a valid position.
Bacteria provide an excellent example. What is a bacterial species? There is more genetic diversity in a petri dish of E. coli than there is in the entire human species. So it's not necessarily a matter of genetic diversity. It's not a reproductive barrier like between humans and macaques, because bacteria don't reproduce sexually. Many bacterial 'species' are defined simply by how they make us sick, and how we can kill them so they don't make us sick. In this case, rather minuscule genetic changes (i.e. mutations conferring resistance to antibiotics) make a hell of a difference to people. So is that microevolution or macroevolution? If you're dying of an infection caused by resistant bacteria, I'd say that's about as real as macroevolution gets.
What about humans? Recent research shows the difference, genetically, between living humans and humans who lived 20,000 years ago is greater than the genetic difference between humans who lived 20,000 years ago and humans who lived 200,000 years ago. Does that mean living humans are a different species than humans who lived 20,000 years ago? Science will not and can not ever answer this question with observable, empirical evidence (unless, of course, time travel gets invented, ha).
The reason why evolution, both its micro and macro varieties, is taught as a legitimate science is that like other sciences, it just plain works. We can use evolutionary theory to predict what will happen in the future based on our understanding of what happened in the past. Look at how the CDC recommends combating diseases today.
The reason why evolution is subject to special criticism is that it challenges traditional religious beliefs. That is, you're descended from an ape-like animal that lived in Africa 6,000,000 years ago, not Adam and Eve 6,000 years ago. Unless you believe the Bible is the literal, revealed Word of God, you shouldn't deny evolution because nothing about evolution is contradictory to what most people consider the heart of faith. It's similarly unfortunate that a few outspoken atheists use evolution to argue against faith, counterproductively polarizing what shouldn't be a debate at all for anyone who isn't an extremely conservative religious person.