Lots of things don't preserve well. Fossils are rare indeed! Time wounds all heels!
But when one is looking for an excuse to dismiss evolution, even a tiny gap or "missing link" looks good.
They ignore the tens of thousands of good fossils we do have as "inconveniences" to be readily dismissed because they don't believe in that evilution stuff anyway. Because they need to destroy people's trust in science, in order to destroy people's trust in evolution, they pervert the scientific method. Here's a good quick explanation of science:
Piling up facts is not science--science is facts-and--theories. Facts alone have limited use and lack meaning; a valid theory organizes them into far greater usefulness.CS/ID has to IGNORE old facts and hope for no new facts; and it discloses no unsuspected facts (i.e., no predictive power or falsifiability). It has to redefine "theory" to mean "proved to 199 decimal places" for evolution, but to "whatever the bible says" for CS/ID.A powerful theory not only embraces old facts and new but also discloses unsuspected facts.
And their understanding of evolutionary science is very limited, and probably derived from the CS/ID websites. This is typical:
"Where are the bones of australo-pithecus versions of monkeys?
Didn't monkeys split off from the ape line many million years before the ape line began to diverge into early apes (including Australo), modern apes, and humans? So why should there be an Australo on the monkey side? That was a unique development on the ape side. (Duh!)
If the question is where are the precursors on the monkey side, they are there too! Maybe a few gaps in the various branches, but its a pretty big and solid tree.
Actually, subconsciously, I think they do. Their arguments against evolution are uniformly juvenile and lacking in substance, and keep being repeated over and over again, despite constant refutations. Consciously, they believe they're fighting a rear-guard action against the forces of evil. Deep down inside, though, they realize those forces aren't evil and actually make good points, which only causes them to redouble their efforts.
The earliest primitive primates are about 55 million years ago. The old-world new-world split comes about 36 million years ago. Apes split from monkeys IIRC about 30 million years ago. The line leading to humans diverges from the line leading to chimps 5-7 million years ago.
"But when one is looking for an excuse to dismiss evolution, even a tiny gap or "missing link" looks good.
Not so long ago I tried to perform the calculations needed to determine the probability of a specific fossil being found . About 15 minutes into it the variables became so numerous that I simply gave it up. I wish a few creationists would try that calculation so they could see how difficult it can be to find fossils for specific lineages and how remarkable it is we have as many as we do.