You're twisting the analogy in a way that clouds its real meaning.

The point is that authorized service shops are provided with the training to perform repairs on these things, so whether the display/glass is glued to the body or not, people are going to be able to take their machines to a shop, have it repaired, and receive it back in working condition. The iMac, if we're following the analogy in an honest way, doesn't have its hood welded shut. (Because iMac mechanics can, in fact, repair them, even if it is more difficult.)

Further, as far as the user is concerned, breaking out a heat gun is just as inaccessible as buying a Torx screwdriver (they don't own one, I promise) and suction cups to pull the glass and display off the old model. They're going to a repair shop or an Apple store 99% of the time.

That's the problem, "authorized shop". The only reason you need to be "authorized" is to give Apple money for upgrading something that you own. It's a lock-in scheme.

Imagine having to go to a Toyota or Honda dealer just to get a battery upgraded, and that it cost 10x more than replacing the battery in a Ford or Chevy at a 3rd party dealer. The battery is no different, just the manufacturer.

Also, what if you don't live in an area with an authorized Apple store? I think there's only 2 Apple Stores in my state, and if I drive south, the next authorized Apple reseller is 4 hours away (I don't think they even do repairs). On the flip side, there are PC repair stores peppered in nearly every town.

That's like saying that the only place you can get your car repaired is 2 hours away, even though there are 3 car repair stores that repair literally every other kind of car in your home town. That's a BIG deal!

In most of my old laptops you could replace the memory with a standard philips screwdriver, a 5 minute job even for someone technologically unsavvy.

By requiring a ton of tools and time you are pointlessly making it more difficult (and therefor expensive), regardless of whether the end user repairs it themselves, gets the nerdy kid down the street to fix it or takes it to an Apple store.

You are mistaken. Have a look under the hood of a Boxster. Oops, no engine there. Check the trunk? Nope, not there either.

You can't get to the engine without pulling it out from underneath, and yet Porsche owners and mechanics are both perfectly happy with the situation.

A Porsche is probably a weird example. I'm assuming the put the engine there for some specific reason like increasing traction on the rear wheels that only really makes sense in a sports car. The performance gain justifies making maintenance more difficult.

The majority of cars are FWD and stick the engine in the under the hood where it's easy to get at because practicality is more important.

Right, and Macs are optimized for performance and physical aesthetics, not practical servicability. Sound familiar?

I really don't buy that argument. The "optimized for performance" statement is pretty much a marketing ploy to downplay Microsoft (who doesn't make hardware, but that's changing).

The only argument here is for the GPU. Apple has put in a lot of work to maximize usability by targeting a specific GPU/CPU combo. RAM is a constant that doesn't really play into the design of the OS, since all RAM manufacturers make the same thing, but with different guarantees.

RAM is about the easiest thing to upgrade, second maybe to a hard-drive. This used to be trivial to upgrade, but now they're making it unnecessarily difficult to lock in customers to paying out the nose for something that should be a simple and cheap upgrade. They're operating on insane margins in the RAM arena (and CPU arena, but that's a different story).

Not sure what the performance or aesthetic improvement would be in this case?

Why the superior weight distribution greatly improves handling of course. How else could Macs feel so snappy?

"Welding the hood shut" is just an imprecise way of saying "rendering the vehicle unserviceable by 3rd parties." The actual location of the engine is a pointless tangent.

In fact there are attempts to limit the serviceability of cars, and these attempts are harmful to independent mechanics.