You're assuming an Apple user is meant to service their own product. That's not the case as far as Apple is concerned. You have an issue, you drop by the Apple store (or send your device in) and they repair it for you.
Determining good-ness or bad-ness of a design has to take into account the intended usage and design goals. Whether a customer should be able to repair their device easily/at all, is a whole separate topic. Apple doesn't think so and their design decisions have clearly reflected that over the decades. As far as that goes, whether the end user has to dig through 20 layers of hardware before cleaning a fan is irrelevant. What's relevant is whether Apple employees who'll be fixing/cleaning these devices will be wasting too much time for the most frequent support requests. That's what Apple should be (and most certainly is) optimizing for.
Also note that the majority of the end users will not have the time nor the interest to repair their own devices, especially when in most cases, their repair is covered under warranty. A lot of people with the technical skills far more than needed to to the self repair fall into this category as well. I've been modding and hacking expensive hardware for decades mostly for fun, but also for practical reasons, in order to add to/modify behavior of the hardware. Even I have little interest to repair my Apple products I have paid premium dollars on. I increasingly value where I spend my time and I let Apple do my laundry for me.
I must also mention (given the high degree of Apple/Google/Facebook/... bashing on HN) that Apple is among the better, if not the best, manufacturers in terms of warranty service and support (at least where I live). I have requested warranty services for dozens of products and not once have had to "prove" my case, or so much as try to convince Apple of an issue. Compared to every other worse interaction with other brands, I will continue to pay top dollars for Apple products even at the cost of whatever the hot Apple knocking topic of the day is. Having said that, there are of course tools that I need full access and repairability as a given and I never go with Apple in those cases.