Hi Andre,
I'm an avid gamer and a firm believer in Apple products. My experience in Apple portable ownership has included 8 different MacBooks, 3 MacBook Airs and 6 MacBook Pros ranging from across the generations since their release in '06. So I'm pretty familiar with their operating temperatures from an ownership and service standpoint.
With that being said (and out of the way), I'll definitely agree with you that the Intel Core Duo machines ran pretty hot (the 1.83, 2.0 & 2.16) machines. A lot of those cooling issues were addressed with the move to the Intel Core 2 Duo machines. Plus, my understanding is that as EFI Firmware updates have come out the fan "logic" has improved.
Apple has always had their cooling philosophy to be reactive vs. proactive. I gave that SMCFanController application a go a while back on one of my machines and watched the internal temperature rise almost 44 degrees (F) before the fans budged above 2000 RPM. So yes, I'll absolutely agree with you that some level of sacrifice would have to occur in cooling to ensure the sleek, slim, look that these machines have had for many years.
However, I also know that Apple has never called their portable computers, "laptops" and they've always referred to them as portable computers in their official documentation on support sites, product marketing materials and included literature.
The design nature of the heat sink to dissipate heat through the enclosure makes design sense and I know when using anyone of my machines as it designed to be used has always been a great experience.