I do not agree.
First, I don't know where that post came from earlier claiming to be from Apple that says the Leopard and Snow Leopard behavior was accidential. In my view, that is not correct. Apple had prior knowledge base articles that CLEARLY detailed every step of attaching an external display, closing the Mac so it would sleep, and then re-waking the Mac with a Bluetooth or USB peripheral.
How could this have been accidental when for at least the entire life of Leopard and Snow Leopard this was taught by Apple articles?
That is my main problem with what is claimed in your post. This was not an accidental feature. It was how it was designed to work. It would not have survived and been documented for so long as an accident.
Second, through the capabilities already provided in the Displays preference pane it would be very easy for Apple to engineer an on-off switch. They already have all the code written to detect displays; it has worked for years. They also have the code written to disable a display through the sleep mechanism. All they have to do is change when that code is activated. I think it is splitting hairs to say we don't know how easy it is. Everything is easy or hard depending on our perspective. It is a matter of what is a priority. But enabling this when the display detection and disabling code is already there is easier than writng that code from scratch.
Third, you mention that the keyboard doesn't vent significantly. Why be so petty when you admit that the increased surface area of aluminum that is exposed to ambient when the case is open is increased? Who cares whether the cooling comes from aluminum or through the keyboard -- either way keeping the case closed is not a heat help. No one has ever argued that keeping the case closed is better. It is at least incrementally worse. So why not allow for a solution, obviously already in use by many given the comments here, that allows for at least marginally better heat flow. (My experience, like the proof offered earlier, is that the difference is much more than marginal.)
A few additional comments:
I think this choice was made more for simplicity than anything else. I agree that Apple thinks a closed case still puts the computer into operating fully within specs, even if it is hotter. (Whether that is true is up for debate, but I do believe they have extensively tested this.) I believe they had service calls and genius bar visits (which they do carefully log) that didn't understand why the internal display didn't light up when the case was opened. People didn't know to go into the monitors preference panel and do a "detect displays" if they really did want the monitor on.
Apple sees: People find it easier to learn that case open = monitor on; case closed = monitor off. (And external display works whenever connected.) Since the computer still runs within engineering specs with this simpler paradigm, it's more simplicity and they design to that.
We users who are a bit more sophisticated and desire a cooler computer (or better WiFi -- same arguments) are probably in the minority and Apple figured it might be able to take the complaints.
My experience tells me that Apple WILL listen. It may take a while, because they are never knee-jerk reactionary. I have had many issues with Apple products over the years and the ones that weren't just simply broken hardware were all eventually fixed within a few months with software updates. Apple unofficially monitors this board and officially monitors the feedback channels and comments at genius bars and by phone. They will learn that they have an engaged user base who sees value in having this changed, and they will likely take the time to think about the best solution. (It surely won't involve a magnet -- grin.) It may be the on-off switch we've been discussing or it may be something more elegant. I can almost completely assure you it will not be regression to the Leopard and Snow Leopard behavior for the simplicity argument I made earlier.
In the meantime, I will use the magnet. It's far from ideal, and I don't and won't like it, but it is working for me with the least hassle. For now.
