1. Its not basically insecure, but you do need to ensure that you have the system configured. Basic tools available also permits an increased level of security.
2. If people want a fisher price interface, then yes use mac os
Seriously, what the windows UI/UX has wrong is lack of constancy, what it get's right is configuration and customization. Tools from stardock highlight the flexibility and freedom that macOS lacks.
3. I'd say the ease of scanning your home network, is a lack of knowledge on your part, not an inherent flaw in windows
4. No argument, but in all truthfulness, the need to go into the registry is nearly non-existent and MS has done a lot to minimize any possible registry issues. I maintain desktops and windows servers and the need to make a change in the registry is a rarity.
I actually prefer to use windows, I find the amount of control you have in working with the OS superior to that of macOS. while Linux offers greater control, it lacks apps. I think you're confusing preference with objectivity, Is Windows perfect, no far from it. Is macOS, or Linux perfect? Nope they have their own issues, both with bugs and design choices.
Get the best tool that fits your preferences and needs, one platform is not inherently weaker then the other.