So in your world professionals are happier with the external power supplies that either produce a ton of cable clutter or get tucked away somewhere to overheat and stop working? In my experience I have never had a single internal power supply fail on me (something else has always failed first in a system, or the system's survived until I need to upgrade it), meanwhile I've had at least six external power supplies fail on me despite taking care in where I put them, usually at the cost of tidiness, three of which were on "professional" hard drive products. In a hard drive system that includes a fan anyway, it makes more sense to have an internal power supply, as it can benefit from the same cooling, which is usually all you need to keep one running.
Besides which, any professional in your world that is relying on external power supplies being replaceable is just begging for the RAID controller or some other component to fail inside the unit, rendering your spare power supplies useless, doubly so since so many of them use different connectors.
Any professional who has to work in a room with it. As an example I have an HDD dock I bought that is otherwise dead handy, but has a blue LED that is almost painfully bright to the point that I had tape a piece of thick plastic over it. It was a relatively cheap dock so that's not completely unexpected, but devices marketed at professionals that slap annoying LEDs or non-functional, obtrusive, embellishments onto their enclosures don't exactly inspire confidence about the internals of their devices.
Apple at least usually manages to marry form and function seamlessly together, which is why I like their products as they put thought into the details, even if it occasionally means making compromises (though I respect them for that in most cases).
No, what it does is prove that you didn't really read what I wrote; I gave the Mac Mini as an example of a product with well designed LED, and really as a well made product in general and that any professional device should aspire to.
The LED on the Mac Mini is stylish, but not obtrusive, similar to the rest of the case. Despite being compact it also manages to keep a neat (and capable) internal PSU, and well designed airflow (dust only really builds up just under the cover, where it's easy to remove). It shows what you can achieve with attention to detail, and to be frank it's something that's been sorely lacking from many Thunderbolt devices, which is what makes it especially hard to pay such high premiums for them.