It is the chapters about "things" (physical reality, rather than people) that contain enough information to feel like they such be provable or at least fit into our modern knowledge of how reality/physics/etc works that promote the most controversy. So: creation and Noah are always going to get more focus than most areas, because they stick out like a sore thumb compared to the bulk of the text which is mostly about people and cultures. It isn't a big step to accept "there was a person called X who said Y to Z" - and no real evidence/counter-evidence either way to contend with.
I agree there have been more questions about the flood than many other things, but my interpretation is that many of those have not been asked by "skeptics", but by believers who struggle with it. Embrace this! It illustrates a real problem that many Christians have - which is essentially the site's mantra. In fact, I suspect that it is precisely because it tries to be fairly detailed that makes it so hard to accept - in that when the details are placed under the modern eye (no matter whether by a believer or skeptic), it does have significant issues. Contrary to some Christians' view that this is a mostly non-miraculous event (about human endeavour), if you don't accept many many many miracles, it requires a massive "suspension of disbelief" to read it. The fact is that there are a lot of important problems, that interestingly wouldn't have been obvious to a writer without modern knowledge - but modern or not they would have needed solving at the time.
Hence the problem is that for many believers it has enough detail to cause alarm bells that doing things with a global flood simply wasn't a sensible approach to the problem, and that just "vanishing" the people you don't want would be simpler and require less supernatural intervention.
Additionally tied into this is the growing field of history: most historians agree that there is plenty of cultural evidence to support one or several significant floods, but not really as described in the Bible, and issues such as cultures of similar and older ages to the supposed chronology dates. Don't shoot the messenger, but: this then prompts the question:
Is there a simpler explanation? Is this just one culture's way of rationalising a flood event that was significant and frightening to them, which uprooted their society and was beyond their ability to comprehend?
Substitute "flood" for any physical event; the answer to questions such as these are... Well, each religion has an answer, and none of them agree.