IME larger companies are more likely to adopt newer OSes because they have a larger IT department who can spare a person or two to validate the new OS with their hardware and mission-critical software. Someone at the top of the IT food chain will delegate the job and leave that person or persons alone to get on with that job. It's a worthwhile task when talking about eventual rollout to thousands or tens of thousands of machines because it'll need to be done eventually anyway, and they might as well get ahead of it to give themselves plenty of time to tackle compatibility and problems, potentially with custom or in-house software.
Smaller companies where you have a team of maybe one or two people managing IT don't have the time, resources, or willpower do do the compatibility testing that Microsoft, hardware vendors, and software vendors inevitably fail to fully get right before an OS launch. Not only do they lack the time and resources to test, they likely play it safe because the attitude is "why should I/we beta test this new OS for Microsoft when someone else can trip over the problems and fix them for us?". Chances are far higher that there is little to no custom or in-house software that needs to be addressed so a small business will move to a new OS only once the downsides to not upgrading outweigh the effort of upgrading every workstation. They'll be using cheaper, less powerful tools like Smartdeploy and PDQ instead of SCCM and multicast imaging with WOL cloning clients.
Arguably the worst size company for OS upgrades is likely 5-50 staff where the IT budget and manpower doesn't even justify these automation and deployment suites for in-house IT, and is an unncessary expense if the IT is outsourced at a day rate.
