Office 365 works well enough on the web, calligra and libreoffice are compatible enough to make it a non issue. You can even upload and work on odf documents on office 365 these days.
I like having 4k in the living room and I have a chromecast for that but I'd rather not have my gf and kids play 4k content while I am working at home and they all have 1080p or lower laptop screen anyway. You don't miss retina if you never used it.
As for the rest of your experience, I guess it comes from poor buying skills. You don't buy a Dell to run MacOS on it. I purchase my laptops and hardware with linux compatibility in mind.
Saying Linux UI is a poor windows 7 ripoff is a lie. I am actually one of the - usually silent - happy gnome 3 user and I think it is a superior desktop UI to anything Microsoft and Apple have produced so far. You get a very focused window without any distraction from unneeded icons and information everywhere and everything can be piloted quickly with the keyboard but also work flawlessly with a touch screen in tablet mode when I flip my Lenovo Yoga.