PC prices are dropping, yet newer Apple laptops are all over $1K. I think that with decent Windows 10 laptops at sub $499 levels, for many folks it's getting more difficult to justify spending over $1K on your kid's 1st laptop...One reason Apple is popular with college students is that they had hands-on experience with Macs in Middle and High School... The old Whitebook was everywhere, every kid wanted one.
I seriously doubt the price is the core reason. I'm seeing more and more people buying SP4 with specs over $1k for their kids as well, especially for colleges with OneNote on SP4 providing an amazing experience for school.
However, for casual users, more and more are using their smartphone only with no plans to upgrade their current computers. Almost all of my elders are using iPads only and they used to have netbooks 2-3 years ago. They'd pick the more expensive iPads over 100-300$ netbook anytime.
A lot of folks bought Macs because a few years ago, they were technically still the best machines for Windows as well. Now, it is much more difficult to decide Macs over Surface Pros, Dell XPS 13", HP Spectre and Surface Book. Even the recent Samsung's Notebook 9 looks amazing for its weight/size.
Dell out-innovated Apple with its Infinity Display, it made a lot of the techies crave it, even over the rMBPs.
MS has more utilities in its SP4/SB over Apple and for a lot of people, it's worth it. College students are advised to get these over Macs.
Schools are going with Chromebooks for K-12 kids because they're simple and cheap to replace often considering the abuse they go through.
The price isn't the problem. It's the value that's the problem and right now, the value of Macs are declining the more Apple continues to neglect its software, services, and so on. Windows 10 is getting better faster than iOS and OS X combined, services are better at Google/Microsoft than Apple, and Google's Nexus are improving their cameras fast enough to be closer to iPhones every year.