But, to your point -- Apple hardware, like most modern laptops, are built on Intel chipsets and cryptographically signed to prevent tampering by the owner. You're locked out of your own laptop.
If you're concerned about security or even if you just like to hack on the stuff you paid for, it's probably not where you want to be. You have no idea what's going on in there, and it's heavily encrypted at multiple layers to keep you from finding out. See my comment above: you were backdoored before the operating system was even installed. I was too, with my sweet new matte black Dell. (See my comment above).
The sad part is that there are very few modern laptops (if any) that we're not steadily being locked out of. It's not just Apple. It's (almost) everyone. and, of course, it's our phones, too. Check out the libreboot and coreboot websites for some modern(ish) gear that isn't backdoored.
You can say many things about Apple, but at least when you buy their hardware you know exactly what to expect. If you used one of their laptops you've used them all.