You can go buy an overloaded i7 Apple 15” laptop @1799 (only 4gb ram) but 90% of computer buyers will do perfectly fine with a Dell @$500 laptop that has just as good build quality has more modest CPU but has the same 4gb memory. You can blow your $$$ if you want
And chances are that many users will replace that $500 Dell a couple times, before the $1800 Apple is obsolete (they don't tend to wear out). After the $1800 Apple laptop is obsolete, chances are pretty good you can sell it for $800. Meanwhile, your Dell's are pretty much worthless. I won't even bother to go into the fact that your Dell has ~45 minutes of battery life on a charge, compared to ~10 hours on the Mac.
Now, if you look at the facts that the Apple laptop can run Windows or OSX, just as well (and often faster) than your Dell; plus the fact that many things a person will want to do, can be EASILY done on a Mac.
For example, if you look at the beauty and simplicty of iMovie; then compare it to the boatload of turds that cost more, and offer a fraction of the capabilities of iMovie - it's kind of a no-brainer. How often have you wanted to put together a 90 second or 5 minute movie highlight of a family get-together, or a vacation? Have you ever tried to do this with the assorted mish-mash of Windows offerings? Give it a try; then take in a quick demo of what iMovie offers - you'll wind up screaming bloody murder at the HOURS/DAYS of frustration you wasted fighting to make a simple presentation - when iMovie can offer a much more professional solution, in a matter of minutes.