I just read Chris Lamb's platform for this year's DPL elections, where he asks why enterprises do not use Debian by default. In this article, I want to give some answers, although I think Chris is very likely already aware of them, given his track record.
I think Chris is partially right: Marketing is important, whether we like it or not. The ArchWiki example that he mentions, shows that they manage to present relevant content in a very accessible manner. This has in part to do with their organization of the information, and also with them possibly keeping the information better up to date than we probably do (I frequently find better information in the ArchWiki myself.)
Their styling is imho on par with ours, so the difference should lie elsewhere. This may be partially due to them using a different software which has a much bigger userbase than ours, which certainly does contribute to users findig it easier to work with, because they don't need to learn anything new - no new procedures, no new markup language, the software already feels familiar. In short, it conforms more to existing user habits because of the market share of that other software.
In my professional experience, I found that there are a few factors which make other versions of Linux, particularly CentOS and friends, more attractive to enterprises like eg. AWS:
Our support cycle is too short.
These enterprises like to have that 10 years of support and never worry about any ugprades, because after 10 years, you can usually safely throw the machine away. The impact is that the vendor, eg. Amazon, does not need to involve the customer about upgrading their application, which the customer usually does not want to do, and also does not allocate any budget to. The typical customer expects, that once he has his application deployed, it will continue to run without change until he decides to stop running that version of said software, and considers upgrades to be a waste of time an money. Also, both security updates and newer versions of some third-party software become available on older versions of such Linux systems without the need for a big upgrade. The former enables the vendor to say that his platform is secure, and that any breaches are solely the fault of the customer, while the latter enables the vendor to offer new features to the customer without requiring him to upgrade. As an example, I'd like to point to the availability of PHP7 on CentOS 6.8, which is from 2016, but does not deviate too much from even older versions of CentOS and thus require not too much re-learning, with their first 6.x version being released in 2011, alongside Squeeze.
[2018-01] It looks like Snaps are addressing this problem.
As a corollary to that, there is a much clearer separation between the very small core distribution, and the large amount of third-party commercial software.
Also, us having tons of software already included, which eat a lot of manpower, is an underemphasized, so it may not be obvious how Debian can make users' lives easier.
There is a certification system in place, that gives the enterprise some confidence about the abilities of any prospective hires. I am not aware of any certification system for Debian.
The boon and the bane of Debian is the non-commercial nature of it. There is no single commercial entity behind Debian, which results in enterprises not knowing whom to sue, or how long the project will survive. Nevermind that similar problems have occurred with many vendors in the past, but there is a vendor which could be sued, if need be. And it looks like they have enough government backing to not easily go bankrupt, either. But the distrust against volunteer organisations which are as loosely knit as Debian is, runs deep.