I personally do not care for windows 10, and I will list some reasons why.
1: It's not a finished product
Microsoft is changing the way it builds Windows, with the release of Windows 10, the company will no longer release major upgrades. Instead, Microsoft is now offering "Windows as a Service." Technically, Windows will never be considered complete, which means that the operating system will continue to be a work in progress. As a result, we are likely to see more bugs and other issues in the regular basis. Additionally, because we're in the early days, you will see some missing features and inconsistency.
In my personal experience, I've seen some issues including bugs in the Start menu where parts of the menu will just randomly disappear. Some Live Tiles also won't change accent color automatically, and the Start menu will suddenly lose its color scheme.
2: The automatic update dilemma
In the new operating system, Microsoft is also introducing a new way to update. Moving forward out-of-the-box users are required to install every update the company pushes out. On the good side of things, automatic updates are a good thing because it ensures that all users (technical and non-technical) are always running the most up to date version of Windows 10 with the latest security patches. However, on the bad side of things, pushing an update even after being fully tested can cause a serious headache to the end user. For example, there could be issues with graphic drivers, or a new patch wasn't fully tested on certain configurations. These and other scenarios can happen anytime, and if you're not a technical user, chances are it will be very frustrating trying to go back to the last known good configuration.
3: Privacy concerns
Since the operating system launched on July 29th, there has been a lot controversy of what information Microsoft collects to improve its services and functionality in Windows 10. If you agree to install Window 10 on your computer, you will be giving Microsoft consent to collect, by default, information about you, devices, application, search queries, application usage, and even when you use voice input such as speech-to-text. So, if you don't feel comfortable with the information the company collects, probably Windows 10 isn't for you. However, keep in mind that Microsoft is very clear on what it collects and Windows 10 provides some ways to control your privacy in the privacy tab.
There are also some good reasons such as dx12 and Cortana if you like a AI. Hope I was some help
