Probably talking about WDS/MDT/SCCM for managing and deploying Windows systems in bulk. The process for capturing a baseline for a pre-updated, pre-device-drivered, pre-configured image of Windows 7 and up is...painful, to say the least. And that's just on Windows 7 - Windows 8 introduced Audit Mode and deprecated the tools used by Windows 7 just when people were getting used to them since DISM and fighting with integrating updates in a way that doesn't see a reboot-mandating update breaking the whole chain is one headache after another. Then there's the convoluted amalgamation of tools in the server-side deployment suite like Windows Deployment Server, Microsoft Deployment Toolkit, System Image Manager, and System Center Configuration Manager.
Yes, it can be learned and understood. But for a lot of organizations' understaffed IT departments, it's a VERY daunting mountain to climb when there are other things to worry about and so a lot of admins end up either installing and configuring individual systems one at a time the old fashioned way, or turning to third-party tools to fill in the gaps.