I am getting very fed up with this "You don't have to use an option if you don't like it" argument, as though it's some magic bullet to get away with not having to discuss the respective pros and / or cons of a particular feature. Eg: However pointless it may be, Apple should include it nonetheless because "I don't have to use it if I don't like it".
I just feel it's pointless and has no reason to exist. Apple products have never been about having the most features or being the "most useful", but about distilling the purest mixture of form and function. It's like how the iPhone has never had expandable storage or removable batteries even though "people don't have to use them if they don't need the extra space". It's about cutting out everything that doesn't make contribute to the final vision of said product even if, like you said, it's entirely optional and I don't lose anything by not booting macOS on my iPad and continuing to use it like a giant iPod touch.
So yes, to answer your question, the main reason why I prefer Apple products is because of their focus on minimalism and purity in design, as well as their audacity to say "we believe this one feature is worth more than every other feature combined" and aren't afraid to stand by those decisions.
Maybe there are some people for whom an iPad running macOS would be an ideal fit, but the Apple I know wouldn't compromise their singular vision of their products in the name of providing more functionality and I respect Apple for that.